Glossary

Aberrant

Aberrant is an adjective pertaining to a deviation from normal.

Aberration

Aberration is the process of deviating from normal, a deviation.

Ablation

Ablation is the destruction of tissue, often by cautery, cryotherapy or laser.

Ablative

Ablative is an adjective pertaining to ablation, the destruction of tissue by laser, cautery, chemicals, surgery, or radiotherapy.

Abnormalities

Abnormalities: plural of abnormality; a noun for not normal things. Abnormalitites are uncharacteristic or unusual.

Abnormality

Abnormality is a noun for a not normal thing. An abnormality is something that is uncharacteristic or unusual.

Abscess

Abscess is a localised collection of pus.

Abscesses

Abscesses: plural of abscess; localised collections of pus.

Acantholysis

Acantholysis is a histological term for the separation of keratinocytes within the epidermis due to the loss of adhesion between keratinocytes.

Acantholytic

Acantholytic is an adjective used in histology to describe the loss of keratinocyte cohesion resulting in 'floating cells'.

Acanthoma

Acanthoma is a benign tumour located in the prickle cell layer of the epidermis. There are several specific forms of acanthoma.

Acanthosis

Acanthosis is a histological term for thickening of the epidermis and elongation of the rete ridges due to thickening of the spinous layer and enlargement of rete pegs.

Accentuate

Accentuate is a verb meaning to make more obvious or noticeable.

Accentuated

Accentuated pertains to the verb to accentuate; to make more obvious or noticeable.

Accentuation

Accentuation is the process of making more noticeable or obvious.

Achromia

Achromia means loss of colour. In the skin achromia is also called leukoderma or depigmentation, and means a lack or absence of melanin.

Acneform

Acneform is an adjective used to describe a resemblance to acne.

Acneiform

Acneiform is an adjective used to describe a resemblance to acne.

Acral

Acral is an adjective relating to or involving a distal site, eg, ear, finger, toe, nose, penis and nipple.

Acrochordon

Acrochordon is a fibroepithelial polyp of the skin, commonly known as a skin tag.

Acrochordons

Acrochordons: plural of acrochordon; fibroepithelial polyps of the skin, commonly known as skin tags.

Acrokeratoderma

Acrokeratoderma is skin thickening of the hands and feet, usually due to hyperkeratosis.

Actinic

Actinic is an adjective pertaining to sun or ultraviolet radiation.

Actinic keratoses

Actinic keratoses: plural of actinic keratosis; scaly skin spots with some keratinocyte atypia caused by chronic sun exposure.

Actinic keratosis

Actinic keratosis is a scaly skin spot showing some atypia of keratinocytes caused by chronic sun exposure.

Active substance

Active substance is an ingredient in a product that has the therapeutic effect.

Active substances

Active substances: plural of active substance; ingredients in a product that have the therapeutic effect.

Acuminate

Acuminate is an adjective used to describe a sharp and tapered point.

Acute

Acute is an adjective describing a sudden onset, sharp rise, or short course.

Adenocarcinoma

Adenocarcinoma: type of cancer derived from a mucin-producing gland.

Adenoma

Adenoma is a benign epithelial tumour with glands and gland-like structures.

Adenomas

Adenomas: plural of adenoma; benign epithelial tumours with glands or gland-like structures.

Adenomata

Adenomata: plural of adenoma; benign epithelial tumours with glands or gland-like structures.

Adenomatous

Adenomatous is an adjective used in histology to describe having glands and gland-like structures.

Adhesion

Adhesion is the process of the sticking together of components, eg, adhesion between keratinocytes.

Adipocyte

An adipocyte is a cell that stores fat. In the skin, adipocytes are located in subcutaneous tissue.

Adipocytes

Adipocytes are cells that store fat. In the skin, adipocytes are located in subcutaneous tissue.

Adipose

Adipose is fat.

Adipose cell

Adipose cell is a fat cell, also known as a lipocyte or adipocyte.

Adipose cells

Adipose cells: plural of adipose cell; fat cells, also known as lipocytes or adipocytes.

Adjacent

Adjacent is an adjective meaning to be next to or adjoining.

Adjunctive

Adjunctive is an adjective for additional, incidental, or subordinant.

Adjunctive therapy

Adjunctive therapy is an additional, often milder, treatment added to improve efficacy or safety of a therapeutic agent.

Adjuvant

Adjuvant is a noun and adjective meaning helper or helpful. An adjuvant is an extra agent added to improve efficacy, for example added to immunisations to improve the immune response. Adjuvant therapies are used after the main treatment for cancer to reduce the risk of recurrence and the chance of secondary tumours.

Adnexa

Adnexa is an accessory or appendage. In dermatology, an epidermal adnexa may be a hair, nail, or sweat gland.

Adnexae

Adnexae: plural of adnexa; appendages or accessories. In dermatology, the epidermal adnexae include hair follicles and sweat glands and ducts.

Adnexal

Adnexal is an adjective pertaining to an adnexa, an accessory or appendage. In dermatology, adnexal may pertain to hair, nail, sweat gland, etc.

Adrenaline

Adrenaline (American terminology epinephrine) is a hormone, neurotransmitter, and drug. The hormone is made in the adrenal gland and is involved in the fight-flight-fright reaction.

Adrenarche

Adrenarche is the increase in adrenal gland activity just before puberty.

Adverse drug reaction

Adverse drug reaction is an unexpected, sometimes harmful, event caused by a medication.

Adverse drug reactions

Adverse drug reactions: plural of adverse drug reaction; unexpected, sometimes harmful, events caused by a medication(s).

Adverse event

Adverse event is any untoward effect or episode occurring during treatment, but not necessarily due to that treatment.

Adverse events

Adverse events: plural of adverse event; any untoward effects or episodes occurring during treatment, but not necessarily due to that treatment.

Adverse reaction

Adverse reaction is an unexpected, sometimes harmful, event caused by a treatment or procedure.

Adverse reactions

Adverse reactions: plural of adverse reaction; unexpected, sometimes harmful, events caused by a treatment or procedure.

Adverse-drug reaction

Adverse-drug reaction is an unexpected, sometimes harmful, event caused by a medication.

Aeroallergen

Aeroallergen is an airborne substance that induces an allergic reaction. A common aeroallergen is pollen.

Aeroallergens

Aeroallergens: plural of aeroallergen; airborne substances that induce an allergic reaction. Common aeroallergens include pollen and fungal spores.

Aerobe

Aerobe is an organism that requires oxygen.

Aerobic

Aerobic is an adjective pertaining to an aerobe(s), a requirement for oxygen.

Aerosol foam

Aerosol foam is a solution with a pressurised propellant that emerges as a foam.

Aetiologies

Aetiologies: plural of aetiology (American spelling etiologies/etiology); causes of a situation such as a disease.

Aetiology

Aetiology (American spelling etiology) is the study of causes and causation. Aetiology is also the cause of a situation, eg, the aetiology of a disease may be an infection.

Aetiopathogenesis

Aetiopathogenesis means the cause and the subsequent development of a disorder.

Agglutination

Agglutination is the process of clumping. 

Agglutinin

Agglutinin is a molecule that binds to particles resulting in agglutination (clumping). An agglutinin is commonly an antibody (immunoglobulin) that may, for example, cause the clumping of red blood cells or pathogens.

Agglutinins

Agglutinins: plural of agglutinin; molecules that cause agglutination, the clumping together of particles such as red blood cells or pathogens.

Aggregate

Aggregate is a noun, verb, and adjective pertaining to collect, collection. For example, an aggregate of cells, and cells may aggregate together, to form an aggregate.

Aggregates

Aggregates: plural of aggregate (noun); collections; or the verb meaning to form a collection or cluster together.

Aggregation

Aggregation is a collection or clustering. For example, aspirin prevents platelet aggregation to form a clot.

Aggregations

Aggregations: plural of aggregation; collections or clusterings.

Agminated

Agminated is an adjective meaning clustered together.

Alanine aminotransferase

Alanine aminotransferase (acronym ALT), also known as alanine transaminase, is an enzyme measured in the blood to monitor liver damage due to medications, viral infections and other forms of inflammation.

Alanine aminotransferase (ALT)

Alanine aminotransferase, or ALT, is an enzyme present in the liver which is indicative of liver damage.

Alanine transaminase

Alanine transaminase (acronym ALT), also known as alanine aminotransferase, is an enzyme measured in the blood to monitor liver damage due to medications, viral infections, and other forms of inflammation.

Allele

Allele is a variant form of a gene found on the same locus of a chromosome.

Alleles

Alleles: plural of allele; variants of a gene found on the same locus of a chromosome.

Allergen

Allergen is a substance capable of inducing an immediate or delayed hypersensitivity reaction (allergy).

Allergenic

Allergenic is an adjective pertaining to the ability to induce an allergy.

Allergens

Allergens: plural of allergen; a chemical or substance capable of causing an allergic reaction.

Allergic reaction

Allergic reaction is a medical event due to an immunological response to an allergen. There are different types of allergic reaction classified by the immune mechanism.

Allergic reactions

Allergic reactions: plural of allergic reaction; medical events due to immunological responses to allergens. There are different types of allergic reactions classified by the immune mechanism.

Allergies

Allergies: plural of allergy; hypersensitivity reactions of various types; abnormal reactions of the immune system to exogenous agents.

Allergy

Allergy is a hypersensitivity reaction of which there are several different types; an abnormal reaction of the immune system to an exogenous agent such as pollen or peanuts.

Allodynia

Allodynia is a symptom, and describes when a non-painful stimulus, such as light touch, elicits severe pain, usually due to inflammation or change in nerve cells.

Alopecia

Alopecia is hair loss due to any cause. Alopecia can be diffuse or localised.

ALT

ALT is the acronym for alanine aminotransferase (alanine transaminase), an enzyme measured in the blood to monitor liver damage due to medications, viral infections, and other forms of inflammation.

Amblyopia

Amblyopia is dimness of vision due to abnormal development of the visual pathway. It results in a 'lazy eye' or 'wandering eye'. 

Amelanotic

Amelanotic is an adjective pertaining to a lack of melanin, the skin pigment.

Amenorrhea

Amenorrhea is the temporary or permanent absence of menstruation.

Amenorrhoea

Amenorrhoea (American spelling amenorrhea) is the temporary or permanent absence of menstruation.

Amino acid

Amino acid is the molecular building block of protein.

Amino acids

Amino acids: plural of amino acid; the molecular building blocks of proteins.

Amino-acid

An amino-acid is the building block of a protein. There are 20 amino acids. The essential amino acids are isoleucine, leucine, lysine, phenylalanine, threonine, tryptophan, and valine (essential because the human body cannot make them and must take them in the diet).

Aminoglycoside

Aminoglycoside is a class of antibiotic. An aminoglycoside inhibits bacterial protein synthesis, and is mainly used to treat Gram-negative infection.

Aminoglycosides

Aminoglycosides: plural of aminoglycoside; a class of antibiotics that inhibit bacterial protein synthesis, and are mainly used to treat Gram-negative infections.

Amniocentesis

Amniocentesis is a procedure to remove amniotic fluid from the pregnant uterus to screen for abnormalities in the fetus.

Amniotic

Amniotic is an adjective pertaining to the amnion, the membrane that encloses an embryo/fetus during pregnancy.

Amorphous

Amorphous is an adjective describing a lack of form or shape.

Amphiphilic

Amphiphilic is an adjective describing the ability to combine with or dissolve in both lipids and water.

Amyloid

Amyloid is an abnormal aggregate of proteins deposited in tissue with characterstic staining and appearance on microscopy.

Amyloidosis

Amyloidosis is a disorder characterised by the formation and deposition of amyloid.

Anaemia

Anaemia (American spelling anemia) is an abnormal low haemoglobin content or number of peripheral red blood cells.

Anaemic

Anaemic is an adjective pertaining to anaemia, a low haemoglobin content or number of red blood cells.

Anaerobe

Anaerobe is an organism that does not require oxygen. It may be a facultative anaerobe meaning it tolerates oxygen in its environment, or a strict anaerobe meaning it is killed by oxygen.

Anaerobes

Anaerobes: plural of anaerobe; organisms that do not require oxygen.

Anaerobic

Anaerobic is an adjective pertaining to not requiring or wanting free oxygen.

Anaesthesia

Anaesthesia (American spelling anesthesia) is a state of chemically induced insensitivity or insensibility. Anaesthesia can be general, when the patient is rendered unconscious; or local, when only a part of a tissue is numb.

Anaesthetic

Anaesthetic (American spelling anesthetic) is an adjective pertaining to anaesthesia, a loss of sensation or sensibility. Common usage also makes anaesthetic a noun meaning a drug used to reduce sensation or consciousness.

Anaesthetist

Anaesthetist (American terminology anesthesiologist) is a medical specialist in the area of anaesthesia. Most commonly anaesthetists administer and monitor general and regional anaesthesics.

Anagen

Anagen is the growth phase of the hair follicle.

Anal

Anal is an adjective pertaining to the anus, the opening at the end of the bowel through which faeces exit the body.

Analgesia

Analgesia is a pain relieving medication.

Analogue

Analogue is something similar that can often be substituted, eg, a drug may be an analogue of another if it has a similar structure and action.

Analogues

Analogues: plural of analogue; similar things, eg, drugs may be analogues if they have similar structures and actions.

Anaphylactic

Anaphylactic is an adjective pertaining to anaphylaxis, an immediate hypersensitivity reaction.

Anaphylactoid

Anaphylactoid is an adjective meaning to resemble anaphylaxis, an immediate hypersensitivity reaction.

Anaphylaxis

Anaphylaxis is an immediate hypersensitivy reaction that can be severe, and potentially fatal, in a sensitised individual.

Anaplastic

Anaplastic is an adjective used in histology to describe specific features usually indicative of malignancy. Anaplastic cells have irregular dark-staining nuclei, and are typically poorly differentiated.

Anatomical region

Anatomical region is one area of the body. Examples the head and neck; trunk; upper or lower limb.

ANCA

ANCA is the acronym for antineutrophil cytoplasmic antibody. Indirect immunofluorescence of neutrophils classifies ANCA into several types: cytoplasmic ANCA (c-ANCA) targets proteinase-3 in the cytoplasm of monocytes and neutrophils: perinuclear ANCA (p-ANCA) targets myeloperoxidase in granules of myelocytes, promyelocytes and neutrophils: atypical ANCA (x-ANCA).

Androgen

Androgen is a class of steroid hormone responsible for the development of male characteristics.

Androgenetic

Androgenetic is an adjective pertaining to a genetic (familial) susceptibility to androgens, the male hormones. It is typically used to describe a form of patterned hair loss, androgenetic alopecia.

Androgens

Androgens: plural of androgen; steroid hormones responsible for the development of male characteristics.

Aneurysm

Aneurysm: a bulging outwards from a weak point in a blood vessel wall

Angina

Angina is a chocking suffocating feeling in the throat.

Angioedema

Angioedema describes rapid and temporary swelling deep in the skin or mucous membranes.

Angioendotheliosis

Angioendotheliosis: proliferation of endothelial cells within blood vessels.

Angiofibroma

Angiofibroma is a family of benign (non-cancerous) tumours composed of increased dermal fibroblasts in a collagenous stroma, and numerous dilated dermal blood vessels.

Angiofibromas

Angiofibromas: plural of angiofibroma; benign tumours composed of increased dermal fibroblasts in a collagenous stroma, and numerous dilated dermal blood vessels.

Angiogenesis

Angiogenesis is the formation of new blood vessels.

Angiogenic

Angiogenic is an adjective pertaining to angiogenesis, the formation of new blood vessels.

Angiogram

Angiogram is a radiograph that displays blood vessels or lymphatic vessels.

Angiography

Angiography is the radiological process to display blood vessels or lymphatic vessels.

Angiokeratoma

Angiokeratoma is a capillary vascular malformation composed of epidermal hyperkeratosis overlying a cluster of dilated upper dermal capillaries.

Angiokeratomas

Angiokeratomas: plural of angiokeratoma; capillary vascular malformations composed of epidermal hyperkeratosis overlying a cluster of dilated upper dermal capillaries.

Angiolipoma

Angiolipoma is a benign encapsulated tumour composed of fat lobules and numerous capillaries. It may be infiltrating or non-infiltrating, solitary or multiple, painful or asymptomatic.

Angiolipomas

Angiolipomas: plural of angiolipoma; benign encapsulated tumours composed of fat lobules and numerous capillaries.

Angioma

Angioma is a benign collection of dilated congested blood vessels. On the skin an angioma typically presents as a red papule. The cherry angioma is a common example.

Angiomas

Angiomas: plural of angioma; benign collections of dilated congested blood vessels. Cherry angiomas are commonly seen on the skin.

Angiomatosis

Angiomatosis is a group of conditions characterised by vascular malformations or angiomas.

Angiomyxoma

Angiomyxoma, also called a myxoma, is an acquired benign neoplasm composed of a mucinous matrix and prominent dilated capillaries. An angiomyxoma may be solitary or one of many.

Angiomyxomas

Angiomyxomas: plural of angiomyxoma; also called myxomas; acquired benign neoplasms composed of a mucinous matrix and prominent dilated capillaries.

Angiotropic

Angiotropic is an adjective to describe having an affinity for, or moving towards, blood vessels, eg, angiotropic large cell lymphoma.

Anhidrosis

Anhidrosis is the inability to sweat appropriately; it may be due to an abnormaiity of the sweat glands or associated with a neurological lesion or disease.

Annular

Annular is an adjective describing a ring-like or circular shape. In dermatology this may be used for lesions grouped in a circle, or a ring-shaped lesion as in granuloma annulare.

Anogenital

Anogenital is the adjective pertaining to the area around the anus and genitals.

Anorectal

Anorectal is an adjective pertaining to the rectum, the final section of the bowel, and anus, the opening to the outside through which faeces exit the body.

Antenatal

Antenatal, or prenatal, is an adjective meaning before birth, eg, antenatal checkup.

Anterior

Anterior is an adjective to describe being towards the front or before. In anatomy, anterior location means on the front (ventral) surface of a body part, eg, the anterior eye meaning the front of the eye.

Anti-inflammatories

Anti-inflammatories: plural of anti-inflammatory; drugs used to treat or prevent inflammation.

Anti-inflammatory

Anti-inflammatory is an adjective used to describe reducing or combating inflammation, eg, an anti-inflammatory drug. Common usage is as a noun, ie, an anti-inflammatory (drug).

Anti-neoplastic

Anti-neoplastic (antineoplastic) is an adjective used to describe a process or agent that inhibits the proliferation of tumour cells.

Antibodies

Antibodies: plural of antibody; immunoglobulin proteins produced by plasma cells directed against specific antigens including infections and toxins.

Antibody

Antibody (acronym Ab) is an immunoglobulin, a protein produced by plasma cells directed against a specific antigen including infections and toxins.

Anticonvulsant

Anticonvulsant is an adjective and noun pertaining to the prevention of convulsions, typically used to describe a family of drugs for the treatment of epilepsy. Common usage makes it a noun, ie, an anticonvulsant (drug).

Anticonvulsants

Anticonvulsants: plural of anticonvulsant; drugs that prevent convulsions, typically used to treat epilepsy.

Antigen

Antigen (acronym Ag) is any substance that evokes an immediate or delayed immune response.

Antigen receptor

Antigen receptor is a membrane-bound immunoglobulin protein on the surface of an immune cell that recognises and binds to a specific antigen.

Antigen receptors

Antigen receptors: plural of antigen receptor; membrane-bound immunoglobulin proteins on the surfaces of immune cells that recognise and bind antigens.

Antigenic

Antigenic is an adjective pertaining to an antigen(s), a chemical that evokes an immediate or delayed hypersensitivity reaction.

Antigens

Antigens: plural of antigen; substances that evoke an immediate or delayed immune response.

Antimicrobial

Antimicrobial is an adjective that means being against a microbe; it describes the action of killing or slowing the growth of microorganisms such as bacteria, viruses, or fungi. Common usage also makes antimicrobial a noun, ie, an antimicrobial (drug).

Antimicrobials

Antimicrobials: plural of antimicrobial; agents that kill or slow the growth of microorganisms such as bacteria, viruses, or fungi.

Antineoplastic

Antineoplastic is an adjective used to describe a process or agent that inhibits the proliferation of tumour cells.

Antineutrophil cytoplasmic antibodies

Antineutrophil cytoplasmic antibodies: plural of antineutrophil cytoplasmic antibody (acronym ANCA). Indirect immunofluorescence of neutrophils classifies ANCA into several types: cytoplasmic ANCA (c-ANCA) targets proteinase-3 in the cytoplasm of monocytes and neutrophils; perinuclear ANCA (p-ANCA) targets myeloperoxidase in granules of myelocytes, promyelocytes and neutrophils; atypical ANCA (x-ANCA).

Antiproliferative

Antiproliferative is an adjective used to describe a process or agent that reduces the ability of cells to replicate, eg, antiproliferative drugs may be used to treat cancer.

Antiviral

Antiviral is an adjective to describe being against viruses, eg, an antiviral drug. Common usage also makes antiviral into a noun, ie, an antiviral (agent).

Anus

Anus is the opening at the end of the bowel, through which faeces exit the body.

Aortic

Aortic is an adjective pertaining to the aorta, the very large artery in the chest and abdomen that leads away from the heart.

Aplasia

Aplasia is the failure to develop, as in aplasia cutis.

Aplastic/aplasia

Aplastic refers to incomplete or defective development of an organ. It is often used to refer to absence of blood cells in aplastic anaemia.

Apocrine

Apocrine is an adjective pertaining to glands that form a secretion by releasing cytoplasm.

Apocrine gland

Apocrine gland is a scent gland mostly found in the armpits and groin which becomes active after puberty.

Apocrine glands

Apocrine glands: plural of apocrine gland; scent glands mostly found in armpits and groin which become active after puberty. Apocrine sweat is oily, thick and odourless; the smell derives from bacterial decomposition.

Apoplexy

Apoplexy comes from the Greek to mean a seizure or striking down. In medicine it was used for bleeding into an organ, but now is rarely used except to describe bleeding into the pituitary gland (pituitary apoplexy).

Apoptosis

Apoptosis is the regulated, normal physiological process by which a cell undergoes self destruction in response to signals from the cell nucleus.

Apoptotic

Apoptotic is an adjective pertaining to apoptosis, the normal process by which a cell undergoes self-destruction.

Appendage

Appendage is an additional thing or supplement.

Appendages

Appendages: plural of appendage; additional things or supplements. The skinl appendages are things additional to the epidermis and include eccrine (sweat) glands, apocrine (scent) glands, pilosebaceous structures (hair and oil glands) and nails.

Aquagenic

Aquagenic is an adjective pertaining to being caused by water, usually due to contact with water.

Arachnid

Arachnid is an arthropod with four pairs of legs, eg, spider, mite.

Arachnids

Arachnids: plural of arachnid; arthropods with four pairs of legs, eg, spiders, mites.

Arborising

Arborising (arborizing) means treelike branching.

Arciform

Arciform is an adjective to describe an arched or bow shape.

Arcuate

Arcuate is an adjective to describe an arched or bow-shape.

Areola

Areola is a circular area. In anatomy the areola is the pigmented circular area around the breast nipple. It is also used in dermatology to mean a red ring around an inflamed spot.

Areolae

Areolae: plural of areola; circular areas. In anatomy the areolae are the pigmented circular areas around the breast nipples. Areolae is also used in dermatology to mean red rings around inflammed spots.

Areolar

Areolar is an adjective pertaining to areola, the pigmented area around the breast nipple.

Array

Array is a large group arranged or organised in columns and rows.

Arrays

Arrays: plural of array; large groups arranged or organised in columns and rows.

Arrector pili muscle

Arrector pili muscle is the small muscle which originates near the basement-membrane zone and attaches to the hair follicle. Contraction of an arrector pili muscle causes the erection of the hair on exposure to cold or fear, to produce a goose-bump.

Arrector pili muscles

Arrector pili muscles: plural of arrector pili muscle; small muscles which originate near the basement-membrane zone and attach to the hair follicles. Contraction of arrector pili muscles causes the erection of hairs on exposure to cold or fear to produce goose bumps.

Arrhythmia

Arrhythmia means a lack or absence of rhythm. A cardiac arrhythmia is an abnormal or irregular heart beat.

Arrhythmias

Arrhythmias: plural of arrhythmia; cardiac arrhythmias are abnormal or irregular heart beats.

Artefact

Artefact: a skin lesion produced by a self-inflicted action.

Arterial

Arterial is an adjective pertaining to an artery/arteries, the muscular blood vessels taking blood away from the heart.

Arteries

Arteries: plural of artery; the muscular blood vessels that carry blood away from the heart.

Arteriole

Arteriole is a very small terminal end of an artery that connects the arterial system to a capillary.

Arterioles

Arterioles: plural of arteriole; very small terminal ends of arteries that connect the arterial system to capillaries.

Arteriosclerosis

Arteriosclerosis, also known as atherosclerosis, is a disease of the arteries in which plaques of fat, cholesterol and calcium form in the vessel wall causing narrowing of the artery lumen.

Arteritis

Arteritis is inflammation of an artery/arteries.

Artery

Artery is a muscular blood vessel that carries blood away from the heart.

Arthralgia

Arthralgia is joint pain without swelling.

Arthralgias

Arthralgias: plural of arthralgia; pain without swelling in joints.

Arthritis

Arthritis is inflammation of a joint(s).

Arthropathic

Arthropathic is an adjective pertaining to an arthropathy, a joint disease.

Arthropathies

Arthropathies: plural of arthropathy; diseases of the joints.

Arthropathy

Arthropathy is any joint disease.

Arthropod

Arthropod is an invertebrate animal with a segmented body, jointed limbs, and a hard shell that is shed periodically.Examples of an arthropod include an insect, spider, and crustacean.

Arthropods

Arthropods: plural of arthropod; invertebrate animals with a segmented body, jointed limbs, and a hard shell that is shed periodically. Insects, spiders, and crustacea are examples of arthropods.

Ascites

Ascites is the abnormal accumulation of fluid in the peritoneal cavity of the abdomen.

Aspartate aminotransferase

Aspartate aminotransferase (acronym AST), also called aspartate transaminase, is an enzyme that can be measured in the blood to detect tissue damage caused by medications, viral infections, or other inflammation. It is found in liver, heart, skeletal muscles, and other tissues.

Aspartate transaminase

Aspartate transaminase (acronym AST), also called aspartate aminotransferase, is an enzyme that can be measured in the blood to detect tissue damage caused by medications, viral infections, or other inflammation. It is found in liver, heart, skeletal muscles, and other tissues.

Asphyxiated

Asphyxiated derives from the verb to asphyxiate, to cause death of an organism by obstructing breathing resulting in a lack of oxygen to tissues.

Asphyxiating

Asphyxiating derives from the verb to asphyxiate, to obstruct breathing and cause death of an organism due to lack of oxygen.

Asphyxiation

Asphyxiation is the process by which the death of an organism is due to lack of tissue oxygen usually caused by obstructed breathing (asphyxia).

Aspirate

Aspirate is the verb to breathe in or out fluid or solid matter into or out from the airways.

Aspirated

Aspirated is a verb and adjective related to aspiration, the breathing in or out of fluids or solid material into or out from the airways, eg, the patient has aspirated vomit, there is an aspirated foreign body.

Aspiration

Aspiration is the process of sucking in and out through the airways. Aspiration-in usually means the breathing in of material foreign to the airways including vomit and foreign bodies. Aspiration-out is the medical procedure to suck out material from the airways including excessive mucus that cannot be coughed up and out.

AST

AST is the acronym for aspartate transaminase and aspartate aminotransferase. AST is an enzyme that can be measured in the blood to detect tissue damage caused by medications, viral infections or other inflammation. It is found in liver, heart, skeletal muscles, and other tissues.

Astigmatism

Astigmatism means there is an irregularity in the curvature of the eyeball resulting in blurry vision.

Asymmetrical

Asymmetrical is an adjective pertaining to a lack of symmetry along an axis. In dermatology asymmetrical may be used to describe the shape of a lesion or the distribution pattern of a rash.

Asymptomatic

Asymptomatic is an adjective to describe the absence of symptoms.

Atherosclerosis

Atherosclerosis, also known as arteriosclerosis, is a disease of the arteries in which plaques of fat, cholesterol and calcium form in the vessel wall causing narrowing of the artery lumen.

Atherosclerotic

Atherosclerotic is an adjective pertaining to atherosclerosis; arteries narrowed by plaque deposition.

Atopic

Atopic is an adjective pertaining to atopy, an inherited tendency to develop allergies such as hay fever (allergic rhinitis), asthma, food allergies, and atopic dermatitis.

Atopy

Atopy is a genetic (inherited) tendency to develop allergies such as hay fever (allergic rhinitis), asthma, food allergies, and atopic dermatitis.

Atrichia

Atrichia is the absence of hair which can be either congenital or acquired.

Atrophic

Atrophic is an adjective pertaining to atrophy, the loss of tissue.

Atrophie blanche

Atrophie blanche is a white atrophic scar typically seen in livedoid vasculopathy.

Atrophoderma

Atrophoderma is a group of conditions characterised by thinning of the dermis; dermal atrophy. There are specific forms of atrophoderma.

Atrophy

Atrophy is the loss or shrinkage of a component of a tissue after having developed normally. In the skin, the epidermis, dermis or subcutaneous fat may show atrophy.

Attenuated

Attenuated is an adjective meaning to be weaker.

Atypia

Atypia is a histological term to indicate variations from normal. Cellular atypia can be malignant or benign. Architectural atypia means an abnormal arrangement.

Atypical

Atypical is an adjective pertaining to atypia, not typical. In dermatology, it may be used to describe unusual-looking lesions such as atypical moles.

Augmentation

Augmentation means enhancement, enlargement, or increased. In dermatology, augmentation may include the injection of fillers into scars and wrinkles.

Auricle

Auricle is the visible part of the ear and the upper part of the heart which is ear-shaped.

Autoamputation

Autoamputation is the spontaneous detachment of an appendage, such as a toe, from the body. This may be due to constriction from a fibrous band or other causes of prolonged ischaemia and tissue necrosis.

Autoantibodies

Autoantibodies: plural of autoantibody; immunoglobulins directed against normal components of the host individual producing them (self, auto).

Autoantibody

Autoantibody is an immunoglobulin directed against a normal component of the host individual producing it (self, auto).

Autoantigen

Autoantigen is a normal self-protein targeted by a host antibody.

Autoantigens

Autoantigens: plural of autoantigen; normal self-proteins targeted by host antibodies.

Autoimmune

Autoimmune is an adjective to describe antibodies directed against a normal host antigen.

Autoimmunity

Autoimmunity is an immune reaction against 'self'; when antibodies are made against a normal body protein resulting in disease.

Autoinflammatory

Autoinflammatory is an adjective describing recurrent inflammatory episodes not associated with an autoimmune disease, malignancy, allergy, immunodeficiency or infection.

Autoinoculation

Autoinoculation is self-inoculation; the spread of infection from one body site to another. In the skin, autoinoculation commonly occurs by scratching or touching an infected site then transferring the infection to another area via the contaminated finger.

Autonomic

Autonomic is an adjective pertaining to being involuntary.

Autonomic nervous system

Autonomic nervous system controls involuntary actions such as the contraction of the heart and secretion from glands.

Autopsy

Autopsy, also called post-mortem examination, is the examination of a body after death, usually performed to determine the cause of death.

Autosomal

Autosomal is an adjective pertaining to a non-sex chromosome. It is usually used in the context of a genetically inherited condition, eg, an autosomal dominant or autosomal recessive condition.

Autosomal dominant

Autosomal dominant is an adjective to describe a genetic disorder in which only one copy of the abnormal gene is required to cause the condition, and that gene is located on a non-sex chromosome.

Autosomal dominant inheritance

Autosomal dominant inheritance is where the inheritance of a characteristic or disease requires only one copy of the mutated gene for expression, and that gene is located on a non-sex chromosome.

Autosomal recessive

Autosomal recessive is an adjective to define a genetic disorder that requires both copies of a gene to be abnormal to cause the condition, and that gene is located on a non-sex chromosome.

Autosomal recessive inheritance

Autosomal recessive inheritance is the inheritance of a characteristic or disease requiring both copies of the gene to be abnormal, and that gene is located on a non-sex chromosome.

Autosomal-dominant

Autosomal-dominant is an adjective to describe a genetic characteristic or disease that requires only one copy of the mutated gene for expression, and that gene is located on a non-sex chromosome.

Autosomal-dominant inheritance

Autosomal-dominant inheritance is where the inheritance of a characteristic or disease requires only one copy of the mutated gene for expression, and that gene is located on a non-sex chromosome.

Autosomal-recessive

Autosomal-recessive is a term used in genetics for a condition that requires both copies of a gene on a non-sex chromosome to be mutated.

Autosomal-recessive inheritance

Autosomal-recessive inheritance is the inheritance of a characteristic or disease requiring both copies of the gene on a non-sex chromosome to be mutated.

Averse reaction

An adverse reaction is a harmful event caused by a medication or procedure.

Axial

Axial is an adjective pertaining to the axis, the centre or midline of a body about which it rotates; thus the axial skeleton is the cranium, sternum and spine.

Axilla

Axilla is the armpit.

Axillae

Axillae: plural of axilla; armpits.

Axon

Axon is a long thread-like extension (dendrite) of a nerve cell (neurone) along which electrical impulses are conducted.

Axons

Axons: plural of axon; dendrites of nerve cells (neurones) along which electrical impulses are conducted.

Azoospermia

Azoospermia is the state of having no live sperm in the semen.

B cell

B cell, also called a B lymphocyte, originates in the bone marrow and is normally involved in producing immunoglobulins to detect and combat infection. An activated antibody-producing B cell is called a plasma cell.

B cells

B cells: plural of B cell; also called B lymphocytes; originate in the bone marrow and are normally involved in the production of immunoglobulins to detect and combat infection.

B lymphocyte

B lymphocyte, also called a B cell, originates in the bone marrow and is normally involved in producing immunoglobulins to detect and combat infection.

B lymphocytes

B lymphocytes: plural of B lymphocyte; also called B cells; bone marrow-derived cells involved in the production of immunoglobulins.

Bacteraemia

Bacteraemia (American spelling bacteremia) is the presence of bacteria in the blood.

Bacteria

Bacteria: plural of bacterium; single-celled prokaryotic micro-organisms that lack a nucleus. Bacteria can live in the environment, on plants and animals, including humans where they may be commensal, harmless, or disease-causing.

Bacterial

Bacterial is an adjective pertaining to bacteria, single-celled prokaryotic micro-organisms.

Bactericidal

Bactericidal is an adjective pertaining to the killing of bacteria.

Bacterium

Bacterium is a single-celled prokaryotic micro-organism that lacks a nucleus. It may be aerobic or anaerobic; environmental or associated with plants or animals; pathogenic or harmless, foreign or commensal.

Balanitis

Balanitis is the inflammation of the glans (head) of the penis.

Basal

Basal is an adjective pertaining to a base, the bottom-most layer.

Basal layer

Basal layer is the bottom-most layer. In the epidermis and mucous membranes the basal layer is called the stratum basale and sits immediately above the basement-membrane zone. It is composed predominantly of columnar or rectangular cells from which new keratinocytes are continuously produced. Scattered melanocytes are also normally found in this layer.

Basalioma

Basalioma is another name for basal cell carcinoma, the commonest form of skin cancer.

Basaliomas

Basaliomas: plural of basalioma; another name for basal cell carcinomas.

Basaloid

Basaloid is an adjective used in histology to describe resembling epidermal basal cells.

Baseline

Baseline is a starting point, a term used in sport and in medicine. In medicine it may be used to define the point before an illness began or before a treatment started.

Basement membrane

Basement membrane is the structure between an epithelium (epidermis in skin) and the underlying connective tissue (dermis in skin).

Basement membrane zone

Basement membrane zone is a thin, non-cellular layer between the epidermis and dermis, composed of various protein structures linking the basal layer of keratinocytes to the basement membrane (hemidesmosomes), and the basement membrane to the underlying dermis (anchoring fibrils). The basement membrane zone has an important role in making sure the epidermis remains attached to the underlying dermis.

Basement-membrane zone

Basement-membrane zone is a thin, non-cellular layer between the epidermis and dermis, composed of various protein structures linking the basal layer of keratinocytes to the basement membrane (hemidesmosomes), and the basement membrane to the underlying dermis (anchoring fibrils). The basement-membrane zone has an important role in making sure the epidermis remains attached to the underlying dermis.

Basophil

Basophil is a granulocytic white blood cell (leukocyte) closely related to mast cells and eosinophils and involved in allergic disease. The cytoplasm of a basophil contains granules that stain blue with basic dyes, ie, basophilic.

Basophilic

Basophilic is an adjective pertaining to staining with basic dyes. Examples in dermatology include the basophilic cytoplasm of plasma cells, basophilic cells of the epidermal basal layer, and basophilic granules in some blood leukocytes.

Basophils

Basophils: plural of basophil; granulocytic white blood cells (leukocytes) closely related to mast cells and eosinophils and involved in allergic disease. The cytoplasm of basophils contains granules that stain blue with basic dyes.

Beau line

Beau line is a transverse depression affecting a nail, due to acute systemic illness stopping nail growth.

Beau lines

Beau lines: plural of Beau line; transverse depressions affecting nails, due to acute systemic illness stopping nail growth.

Benign

Benign is an adjective to describe being mild, harmless, non-cancerous, or having a good prognosis.

Benign keratoses

Benign keratoses: plural of benign keratosis; a general term covering seborrhoeic keratoses, solar lentigines, lichen planus-like keratoses or a combination of these lesions.

Benign keratosis

Benign keratosis is a term used in clinical dermatology and specifically reflectance confocal microscopy to describe the features seen on examination of a solar lentigo, a seborrhoeic keratosis, a lichen planus-like keratosis or a combination of these.

Bilateral

Bilateral is an adjective describing involvement of two sides but does not imply symmetry. Bilateral skin disorders affect both sides of the body.

Biliary

Biliary is an adjective pertaining to bile produced in the liver, stored in the gallbladder, and transported along the bile duct to the duodenum to aid in digestion.

Bilirubin

Bilirubin is a yellow pigment produced in the liver by the degradation of haem.

Binocular

Binocular is an adjective describing the use or involvement of two eyes, eg, binocular vision.

Bioavailability

Bioavailability: the amount of a drug entering into the systemic circulation.

Biocide

A substance or microorganism intended to destroy, deter, disable, or control a harmful organism, eg, disinfectant, preservative, insecticide.

Biofilm

Biofilm is a thin layer of bacteria and secreted polymers adhering to the surface of a structure. A biofilm can form on organic surfaces, such as skin or teeth, or inorganic structures, such as tubes or catheters.

Biomarker

Biomarker is a naturally occurring molecule, gene, or characteristic by which a particular pathological or physiological process, disease, etc. can be identified.

Biomarkers

Biomarkers: plural of biomarker; naturally occurring molecules, genes, or characteristics by which a particular pathological or physiological process, disease, etc. can be identified.

Biopolymer

Biopolymer is a polymer (chain of molecules) in living tissue and cells. There are three classes of biopolymer: polymers of nucleotides (DNA or RNA), polymers of amino acids (peptides or proteins), and polymers of carbohydrates (polysaccharides).

Biopolymers

Biopolymers: plural of biopolymer; polymers (chains of molecules) in living tissues and cells.

Biopsies

Biopsies: plural of biopsy (noun); tissue samples. Biopsies is also a verb meaning the obtaining of a tissue sample, eg, the dermatologist biopsies the skin.

Biopsy

Biopsy is a noun and verb pertaining to a tissue sample, eg, a dermatologist may take a skin biopsy, the dermatologist may biopsy the skin.

Blanch

Blanch is a verb meaning to whiten or make pale, eg to blanch with fear or to blanch vegetables. In dermatology it is used to describe the removal of normal skin colour, erythema or telangiectasis by pressure, indicating the colour is due to blood in dilated surface capillaries and small blood vessels.

Blanching

Blanching is an adjective, verb and noun pertaining to blanch, pallor, paleness, whiteness. In dermatology a blanching rash or lesion is describing the loss of colour, erythema or telangiectasis by pressure, blanching the vegetables, blanching occured.

Blaschko line

Blaschko line is an embryological clonal expansion line in the skin following a roughly linear, segmental pattern. A birthmark may be distributed along a Blaschko line.

Blaschko lines

Blaschko lines: plural of Blaschko line; embryological clonal expansion lines in the skin following a roughly linear, segmental pattern. Many birthmarks appear to be distributed along these lines.

Bleb

Bleb is a small thin-walled blister containing air or fluid.

Blebs

Blebs: plural of bleb; small thin-walled blisters containing fluid or air.

Blepharoconjunctivitis

Blepharoconjunctivitis is inflammation of the eyelids and conjunctiva at the same time.

Blood vessel

Blood vessel is a tube to carry blood around the body. Examples include an artery, arteriole, capillary, venule, or vein.

Blood vessels

Blood vessels: plural of blood vessel; tubular structures including arteries, arterioles, capillaries, venules, and veins, that carry blood around the body.

Brachy-

Brachy- is a prefix meaning short, as in brachyonychia to mean a short nail.

Bradycardia

Bradycardia is an abnormally slow heart rate of less than 60 beats per minute.

Bradykinin

Bradykinin is a naturally occurring peptide in the body involved in inflammation including the innate immune system. It causes smooth muscle relaxation in arteries (vasodilation), but constriction in the gut and respiratory tree. Bradykinin also increases vascular permeability and has a diuretic effect.

BRAF

BRAF is a proto-oncogene that encodes a threonine protein kinase called B-Raf. It is essential for normal cell development and function however mutations in the BRAF gene may result in cancer.

BRAF inhibitor

BRAF inhibitor is a drug that directly targets a mutated BRAF protein to shrink or slow the growth of a tumour.

BRAF inhibitors

BRAF inhibitors: plural of BRAF inhibitor; drugs that directly target a mutated BRAF protein to shrink or slow the growth of a tumour.

Breslow thickness

Breslow thickness, also called Breslow depth, is the thickness of an invasive melanoma in millimetres measured from the granular cell layer to the deepest tumour cell. Breslow thickness is an important prognostic factor so should be measured and recorded on the histology report.

Bromhidrosis

Bromhidrosis is an abnormal or offensive body odour.

Bronchiolitis obliterans

Bronchiolitis obliterans: an inflammatory fibroproliferative disease affecting the bronchioles, causing fibrosis (scarring) and progressive, largely irreversible, lung damage

Bronchospasm

Bronchospasm is the tightening of the respiratory muscles leading to wheeze.

Buccal

Buccal: is an adjective pertaining to the cheek.

Bull's eye

Bull's eye is an adjective or noun pertaining to concentric rings or target. In dermatology, target or iris lesions have a bull's eye appearance.

Bull's-eye

Bull's-eye is an adjective and noun pertaining to concentric rings as in a target. In dermatology, a bull's-eye appearance describes an iris lesion or target lesion.

Bulla

Bulla is a large blister, more than 1 cm in diameter, and containing clear, serous, or haemorrhagic fluid. A skin bulla may be within the epidermis (intraepidermal) or below the basement membrane (subepidermal).

Bullae

Bullae: plural of bulla; large fluid-filled blisters, greater than 1 cm in diameter.

Bullous

Bullous is an adjective pertaining to bulla(e), large blister(s).

Bulls-eye

Bulls-eye is an adjective and noun pertaining to concentric rings as in a target. In dermatology, a bulls-eye appearance describes an iris lesion or target lesion.

Burrow

Burrow is a hole or tunnel. In dermatology, a burrow may be due to a tunneling parasite such as the scabies mite and others.

Burrows

Burrows: plural of burrow; holes or tunnels.

C-reactive protein

C-reactive protein (acronym CRP) is a nonspecific inflammatory marker protein produced by the liver and commonly measured in the blood. An elevated CRP in the blood is associated with infection, tumours and inflammatory diseases.

Cachectic

Cachetic is an adjective pertaining to cachexia, a state of weight loss and poor quality of life associated with cancer, AIDS, and chronic organ failure.

Cachexia

Cachexia is a state of weight loss associated with anorexia, muscle and fat loss, poor quality of life, and fatigue. It is associated with cancer, AIDS, and chronic organ failure such as congestive cardiac failure or renal failure.

Calcification

Calcification is the process of depositing calcium salts in body tissues.

Calvaria

Calvaria, also called calvarium, is the top of the skull.

Calvarium

Calvarium, also called calvaria, is the top of the skull.

Cancer

Cancer is a generic term for a malignant tumour, in which there is uncontrolled clonal cell proliferation and destruction of local tissue, with the potential to spread to distant sites (metastasise).

Capillaries

Capillaries: plural of capillary; very small thinwalled vessels which, in the body, connect the arterial and venous systems.

Capillary

Capillary is a noun and adjective pertaining to being fine, filamentous and hair-like. In the body a capillary is a very small blood vessel connecting between the arterial and venous systems; a capillary tube or capillary action; being related to the vascular capillaries, eg, a capillary bed.

Carbohydrate

Carbohydrate is a chemical compound made up of carbon (carbo), hydrogen (hydr), and oxygen (ate), used as a major source of stored energy in the body.

Carbohydrates

Carbohydrates: plural of carbohydrate; chemical compounds made up of carbon, hydrogen, and oxygen, used as a major source of stored energy in the body.

Carcinogen

Carcinogen is an agent or substance that promotes, causes, or increases the risk of cancer.

Carcinogenic

Carcinogenic is an adjective pertaining to the triggering of cancer development.

Carcinogens

Carcinogens: plural of carcinogen; substances or agents that promote, cause, or increase the risk of cancer.

Carcinoma

Carcinoma is a malignant tumour of epithelial cells. The two most common forms of skin carcinoma are basal cell carcinoma and squamous cell carcinoma.

Carcinomas

Carcinomas: plural of carcinoma; malignant tumours of epithelial cells. The two most common skin carcinomas are basal cell carcinomas and squamous cell carcinomas.

Cardiomyopathy

Cardiomyopathy is any disease of the heart muscle.

Carotenaemia

Carotenaemia (American spelling carotenemia) is elevated beta-carotene level in the blood due to the excessive ingestion of beta-carotene in yellow, orange and green coloured vegetables and fruit. It commonly presents as a yellow or orange skin discolouration especially noticeable in the thick skin of the palms and soles.

Carrier

Carrier is one that carries or holds. In medicine it may be used for an individual who carries a disease without symptoms, typically a genetic disorder or infection.

Carriers

Carriers: plural of carrier; those that carry or hold. In medicine it may be used for individuals who carry a disease without symptoms, typically a genetic disorder or infection.

Caseating

Caseating is an adjective pertaining to cheese, a cheese-like appearance or texture.

Caseating necrosis

Caseating necrosis is a histological term for a specific form of collagen destruction typically associated with granulomas; a mix of coagulative and liquefactive necrosis resembling friable cheese.

Catagen

Catagen is the short involutional phase of the hair cycle.

Cataract

Cataract is defined in medicine as an opacity in the lens of the eye which may cause impaired vision or blindness.

Cataracts

Cataracts: plural of cataract; in medicine are opacities in the lenses of the eyes which can cause impaired vision and blindness.

Catheter

Catheter is a hollow tube used in a medical procedure to drain or infuse liquids or fluids. A urinary catheter is used to drain urine, and a venous catheter used for an intravenous infusion.

Catheters

Catheters: plural of catheter; hollow tubes used in medical procedures to drain or infuse liquids or fluids.

Cationic

Cationic is an adjective pertaining to a cation, a positively charged ion (atom or molecule).

Caudal

Caudal is an adjective pertaining to the tail. A caudal location is on or near to the tail or base of the spine.

Causative drug

Causative drug is a medication responsible for an adverse reaction, such as a rash.

Causative drugs

Causative drugs: plural of causative drug; medications responsible for an adverse reaction, such as a rash.

Cauterise

Cauterise is the verb pertaining to the process of cautery, the destruction or coagulation of tissues using heat or chemicals.

Cautery

Cautery destroys or coagulates tissue using heat or chemicals.

Cellular

Cellular is an adjective pertaining to living cells.

Cephalic

Cephalic is an adjective pertaining to the head. Cephalic location means on or near to the head.

Ceramide

Ceramide is a family of waxy lipid molecules found in cell membranes with important functions in cell regulation and apoptosis. Approximately 50% of the stratum corneum is composed of a ceramide.

Ceramides

Ceramides: plural of ceramide; members of a family of waxy lipid molecules found in cell membranes with important functions in cell regulation and apoptosis. Approximately 50% of the stratum corneum is composed of ceramides.

Cerebral

Cerebral is an adjective pertaining to the brain (cerebrum).

Cerebrovascular

Cerebrovascular is an adjective pertaining to the vascular system within the brain.

Cervical

Cervical is an adjective pertaining to the cervix, that part of the uterus (womb) that opens into the upper vagina. Cervical is also used in anatomy pertaining to the neck, so examples include the cervical spine and cervical lymph nodes.

Cervix

Cervix is that part of the uterus (womb) that opens into the upper vagina.

Cessation

Cessation is the process of ceasing or stopping, eg, the cessation of a drug means the drug is being stopped.

Chancre

Chancre(s): Noun; painless ulcer.

Chancres

Chancre(s): Noun; painless ulcer.

Checkpoint inhibitor

Checkpoint inhibitor is a drug or agent that blocks an inhibitory checkpoint molecule protecting a tumour from immune attack. It is a form of immune therapy (immunotherapy).

Checkpoint inhibitors

Checkpoint inhibitors: plural of checkpoint inhibitor; drugs that block inhibitory checkpoint molecules protecting a tumour from immune attack. Checkpoint inhibitors are a form of immune therapy (immunotherapy).

Chelating

Chelating is an adjective pertaining to chelation, the binding of metals.

Chelation

Chelation is the chemical process by which metals are bound to an organic molecule. In medicine chelation may be used to treat or remove toxic heavy metals, such as lead or mercury, from the body.

Chemokine

Chemokine is a chemotactic cytokine; a signalling molecule that induces chemotaxis in nearby cells. An inflammatory chemokine, for example, attracts leukocytes (white blood cells).

Chemokines

Chemokines: plural of chemokine; chemotactic cytokines; signalling molecules that induce chemotaxis in nearby cells. Inflammatory chemokines, for example, attract leukocytes (white blood cells).

Chemotactic

Chemotactic is an adjective pertaining to chemotaxis, the movement of organisms, cells, or cellular components, in response to a chemical stimulus.

Chemotaxis

Chemotaxis is the movement of organisms, celsl, or cellular components, in response to a chemical stimulus.

Chemotherapy

Chemotherapy is an adjective and noun pertaining to the chemical treatment of disease, eg, chemotherapy drug, chemotherapy is the drug regime to treat cancer.

Chimera

Chimera has two genetically distinct components. In biologics this means one part of the molecule is derived from a mouse and the other part is human. An individual can also be a chimera, usually of the blood system detected during blood typing.

Chimeric

Chimeric is an adjective pertaining to being a chimera, such as an individual or molecule having two genetically different parts. In the case of a biologic agent, this may mean one part of the molecule is derived from a mouse and the other part is human.

Cholestasis

Cholestasis is the buildup of bile or its constituents due to a failure to secrete or blockage.

Cholestatic

Cholestatic is an adjective pertaining to cholestasis; the build up of bile or its constituents.

Cholesterol

Cholesterol is a sterol compound present in all animal fats and oils.

Cholinergic

Cholinergic is an adjective pertaining to acetylcholine, a neurotransmitter.

Chondritis

Chondritis is inflammation of cartilage.

Chorionic villus sampling

Chorionic villus sampling is a procedure removing cells from the chorion of the placenta in the first trimester of pregnancy to identify genetic abnormalities in the fetus.

Chorionic-villus sampling

Chorionic-villus sampling is a procedure removing cells from the chorion of the placenta in the first trimester of pregnancy to identify genetic abnormalities in the fetus.

Chorioretinitis

Chorioretinitis: inflammation of the choroid layer of the retina.

Chorioretinopathy

Chorioretinopathy is a non-inflammatory condition of the eye involving both the choroid and the retina.

Chromatin

Chromatin is the DNA and protein packaged to fit into the nucleus of a cell.

Chromonychia

Chromonychia is discolouration of a nail.

Chromophore

Chromophore is the part of a molecule that imparts its colour.

Chromophores

Chromophores: plural of chromophore; the part of molecules that impart colour.

Chromosomal

Chromosomal is an adjective pertaining to the chromosome, a long chain of genes inherited as a whole.

Chromosome

Chromosome is a long chain of genes; the entity carrying the genetic material of a cell (organism) which is passed to progeny, and is expressed as proteins for cellular functions.

Chromosomes

Chromosomes: plural of chromosome; entities carrying the genetic material of a cell (organism) which are passed to progeny, and are expressed as proteins for cellular functions. Humans have 46 chromosomes in each cell nucleus.

Chronic

Chronic is an adjective pertaining to persistence. It is used in medicine to describe a persistent symptom or sign.

Chronicity

Chronicity refers to the duration of an illness.

Cicatricial

Cicatricial is an adjective pertaining to cicatrix, a scar.

Circumcision

Circumcision is the surgical removal of the penile foreskin.

Circumferential

Circumferential is an adjective pertaining to the circumference. In dermatology it may be used to describe a rash or skin change encircling or encompassing a body part such as a limb or trunk.

Circumferentially

Circumferentially is an adverb pertaining to the circumference. in dermatology it is when a skin change or rash is encircling a body part such as a limb or trunk.

Circumscribed

Circumscribed is an adjective used to describe being welldefined, having a distinct edge.

Cirrhosis

Cirrhosis is the end result of chronic inflammation and scarring of the liver. Common causes of cirrohosis include chronic alcohol abuse and viral hepatitis B and C.

Claudication

Claudication is muscle pain due to arterial insufficiency. Typically claudication occurs in the legs with exerise and indicates arteriosclerosis.

Cleavage

Cleavage is a sharp division or separation into parts.

Cleft

Cleft is a separation, split, or fissure between two parts.

Cleft lip

Cleft lip: a congenital malformation presenting as a split in the upper lip; may be unilateral or bilateral.

Cleft palate

Cleft palate: a congenital malformation presenting as an opening in the roof of the mouth.

Clefting

Clefting is the formation of a cleft, separation, split, or fissure between two parts. In medicine clefting can result from the failure of two embryonal plates to fuse as in a cleft lip or cleft palate. In histology, clefting is used when separation of cells, layers, or constituents is seen, often as a characteristic processing artefact.

Clefts

Clefts: plural of cleft; separations, splits, or fissures between parts.

Clinicopathological

Clinicopathological is an adjective pertaining to the combination of clinical and pathological. Clinicopathological correlation means the diagnosis needs be consistent with both the clinical and pathological findings.

Clod

Clod is a lump of earth. In dermoscopy it may be used to mean a globule, ovoid nest, or lacuna.

Clods

Clods: plural of clod; in dermoscopy clods may be globules, ovoid nests or lacunae.

Clonal

Clonal is an adjective pertaining to a clone; an expansion from a single entity.

Clone

Clone is an expansion from a single entity, so all members are identical.

Clones

Clones: plural of clone; more than one expansion, each from an individual single entity. Members within each of the clones are identical.

CNS

CNS is the acronym for central nervous system; the brain and spinal cord.

Coagulase

Coagulase is an enzyme that converts fibrinogen to fibrin resulting in a blood clot and blood cell clumping. Coagulase is produced by some staphylococci and the coagulase test is used to determine pathogenicity.

Coagulation

Coagulation is the process by which blood forms a clot.

Coagulopathy

Coagulopathy is a disorder of coagulation that results in thrombosis, clotting. There are many forms of coagulopathy and those with skin signs can be divided into systemic coagulopathy and vascular coagulopathy.

Coalesce

Coalesce is a verb meaning to merge together to form one. Skin papules may coalesce to form a plaque.

Coalescence

Coalescence is a noun for a merging of mutiples into a single entity, eg, a coalescence of vesicles into a bulla.

Coalescing

Coalescing is an adjective and verb pertaining to coalescence, the coming together or merging to form one. In dermatology, coalescing papules may form a plaque; papules coalescing into plaques.

Colitis

Colitis is inflammation of the colon (large intestine).

Collagen

Collagen is a large family of proteins with a triple helix structure found in most tissues. In the skin, collagen is an important and major component of the dermis.

Collagenoma

Collagenoma is a variant of connective tissue naevus; a congenital hamartoma of increased dermal collagen without an increase in fibroblast numbers. The Shagreen patch of tuberous sclerosis is usually a collagenoma on histology.

Collagenomas

Collagenomas: plural of collagenoma; variant of connective tissue naevi; congenital hamartomas of increased dermal collagen without an increase in fibroblast numbers.

Collagenous

Collagenous is an adjective used in histology pertaining to collagen, eg, a collagenous stroma.

Collarette of scale

Collarette of scale refers to a rim of fine white scale at the edge of an inflammatory lesion or resolving infectious process.

Colonoscope

Colonoscope is an endoscope, a long tubular instrument with light and magnification, for examining and sampling the large bowel (colon, large gut).

Colonoscopy

Colonoscopy is the visual examination of the colon (large gut, large bowel) using a colonoscope, a specific type of endoscope.

Colposcope

Colposcope is an instrument providing light and magnification for examining the vagina and cervix.

Colposcopy

Colposcopy is an intravaginal examination using a colposcope to provide light and magnification; most often used to identify cervical dysplasia.

Columella

Columella of the nose separates the nostrils, connecting the tip of the nose to the base of the nose. It is the visible outside edge of the nasal septum composed of skin and cartilage.

Comedo

Comedo is a blocked hair follicle (pore) in the skin. Skin cell debris combines with oil (sebum) to plug the follicle. A comedo can be open (blackhead) or closed by skin (whitehead).

Comedogenic

Comedogenic is an adjective pertaining to the formation of comedones, hair follicles blocked with sebum and skin cell debris.

Comedogenicity

Comedogenicity is a measure of the tendency to cause comedones. Cosmetics may be assessed for comedogenicity.

Comedones

Comedones: plural of comedo; pores filled with skin debris, and sebum (oil).

Commensal

Commensal is an adjective and noun pertaining to a close relationship between unrelated organisms without harm to either, and sometimes with benefit to one or both.

Commensals

Commensals: plural of commensal (the noun); typically used for the micro-organisms living on a body surface and forming the microbiome.

Community infection

Community infection is a viral, bacterial, or other type of infection that is common in the general population.

Community infections

Community infections: plural of community infection; viral, bacterial, or other infections that are common In a general population.

Complement

Complement is a system of glycoproteins important in the innate immune system. Activation of the complement cascade results in enhancement of the cellular immune response.

Complementarity

Complementarity is a noun meaning a situation in which two parts match. In biology this may refer to the base-pair matches in double-stranded DNA or RNA, an enzyme matches a substrate, or an antibody matches an antigen.

Compound naevi

Compound naevi: plural of compound naevus (American spelling nevi/naevus); benign melanocytic naevi in which the melanocytes are located in both the epidermis and dermis.

Compound naevus

Compound naevus (American spelling nevus) is a benign melanocytic naevus in which melanocytes are found in both the epidermis and dermis.

Compulsion

Compulsion is a repetitive behavioural or mental act that the individual feels compelled to perform to reduce the distress elicited by an obsession.

Compulsions

Compulsions: plural of compulsion; repetitive behavioural or mental acts that the individual feels compelled to perform to reduce the distress elicited by the obsessions.

Compulsive

Compulsive is an adjective pertaining to a compulsion, an irresistible urge.

Computed tomography

Computed tomography (acronym CT scan) is a diagnostic radiology test that scans the body to produce cross-sectional images of the part.

Computed tomography (CT)

Computed tomography (CT) is a diagnostic radiology test that scans the body to produce cross-sectional images of the part.

Concentric

Concentric is an adjective pertaining to arrangement around a central point, eg, an archery or shooting target is concentric rings around the central bull's eye.

Concomitant

Concomitant is an adjective meaning accompanying or at the same time, simultaneous, eg, concomitant treatments means more than one treatment at the same time.

Concomitantly

Concomitantly is an adverb pertaining to concomitant or simultaneous. Medications may be used concomitantly meaning used at the same time.

Concurrent

Concurrent is an adjective to describe co-existing, happening or done at the same time.

Conduction

Conduction is the process of transferring heat or electricity.

Configuration

Configuration is an arrangement or shape. In dermatology many skin conditions have a characteristic configuration (arrangement).

Confluent

Confluent is an adjective pertaining to confluence, flowing or coming together, eg, confluent pustules.

Congenital

Congenital is an adjective to mean present at birth, born with.

Conjugate

Conjugate is a noun and verb pertaining to the joining together of parts. Examples include the joining of two molecules such as a fluorofor and an antibody to use in direct immunofluoresence, to conjugate a verb in grammar, bacteria conjugate to share genetic material,

Conjugated

Conjugated is the past tense of the verb to conjugate meaning to be paired or joined.

Conjugates

Conjugates: plural of conjugate (the noun); parts paired or joined; and present tense of the verb to conjugate meaning to pair or join together.

Conjunctiva

Conjunctiva is the membrane that covers the inside of the eyelid and surface of the eyeball.

Conjunctivae

Conjunctivae: plural of conjunctiva; membranes that cover the inside of the eyelids and surfaces of the eyeballs.

Conjunctivitis

Conjunctivitis is inflammation of the conjunctiva of the eye.

Connective tissue

Connective tissue is found throughout the body, holding layers or components together. In the skin this refers to the dermis and subcutaneous tissue, connecting the epidermis to underlying layers such as muscle.

Consanguinity

Consanguinity is a close genetic relationship between parents; kinship; having a common ancestor. Consanguinity increases the risk of a child inheriting an autosomal recessive genetic disorder.

Constituent

Constituent is a component, a part.

Constituents

Constituents: plural of constituent; components or parts.

Constriction

Constriction is used to mean a narrowing of something, such as a blood vessel.

Contracture

Contracture is a permanent shortening of muscle, connective tissue, or skin typically resulting in deformity across a joint.

Contractures

Contractures: plural of contracture; deformities caused by permanent shortening of tissues across joints.

Contraindicated

Contraindicated is a verb related to inadvisable, not indicated. In medicine it is used in relation to the inadvisability of a treatment, procedure or investigation, and may be categorised as relatively or absolutely contraindicated.

Contraindication

Contraindication is a reason why a treatment, procedure or investigation is inadvisable. A contraindication may be relative (care needed to proceed, eg, use a lower dose) or absolute (must not proceed). Pregnancy is an absolute contraindication for some drugs and procedures such as x-rays.

Contraindications

Contraindications: plural of contraindication; reasons why a treatment, procedure or investigation is inadvisable. Contraindications may be relative or absolute.

Control

Control can be used as a noun, verb, or adjective, usually pertaining to the power to direct or restrain. In a scientific experiment or clinical trial, a control (noun) is a comparison without an active intervention. Control can be used as a verb for the suppression of a symptom or condition, for example to control itch means to be not itchy anymore.

Controls

Controls can be used as the plural of the noun, or as a present tense of the verb to control (to direct or restrain). In scientific experiments and clinical trials the controls are those used as comparisons with no active interventions.

Convulsant

Convulsant is a trigger for a convulsion, for example, a toxin or drug that causes involuntary muscle contractions. An anti-convulsant prevents convulsions.

Convulsion

Convulsion is the process of having an episode of uncontrollable muscle contractions as can occur with epilepsy.

Convulsions

Convulsions: plural of convulsion; episodes of uncontrollable muscle contractions.

Cord

Cord is a rounded long flexible structure like a rope. Examples in anatomy include the spinal cord, umbilical cord, and spermatic cord. In dermatology palpable linear firm structures deep in the skin may be described as cords as in Dupuytren contracture and Interstitial granulomatous dermatitis.

Cords

Cords: plural of cord; rounded long flexible structures like ropes.

Cornea

Cornea is the transparent layer at the front of the eye.

Corneocyte

Corneocyte is an epidermal cell (keratinocyte) in the stratum corneum (outermost layer of the epidermis) which normally lacks a nucleus.

Corneocytes

Corneocytes: plural of corneocyte; epidermal cells (keratinocytes) in the stratum corneum which normally lack nuclei.

Corneotherapy

Corneotherapy is a medically funded treatment with dermatological cosmetics administered by medical staff.

Cornoid

Cornoid is an adjective meaning horn-like, eg, cornoid lamella is a thin horn-like layer.

Corticosteroid

Corticosteroid is a family of steroid hormones made in the adrenal gland cortex comprising glucocorticosteroids (glucocorticoids) and mineralocorticosteroids (mineralocorticoids).

Corticosteroids

Corticosteroids: plural of corticosteroid; includes glucocorticosteroids and mineralocorticosteroids; steroid hormones made in the adrenal gland cortex or synthetically for use as a topical, inhaled, or systemic medication.

Cortisol

Cortisol, also known as hydrocortisone, is a glucocorticosteroid hormone made in the cortex of the adrenal gland.

Cosmeceutical

Cosmeceutical is a substance or product that claims both cosmetic and therapeutic benefits.

Cosmeceuticals

Cosmeceuticals: plural of cosmeceutical; substances or products that claim both cosmetic and therapeutic benefits.

Cream

Cream, when used in dermatology, is a semi-solid formulation for topical application. A cream may be a water in oil (lipid) emulsion or lipid (oil) in water emulsion. Common usage also makes cream a verb, to apply a cream.

Creams

Creams; plural of cream; in dermatology creams are semi-solid formulations for topical application.

Crepitus

Crepitus is a crackling sound. It can be heard when there is gas in tissues such as gas gangrene; in pneumonia; and when bones rub together after a fracture.

Cribriform

Cribriform is an adjective used to describe something pierced by many little holes.

Cross-reactivity

Cross-reactivity, when used in allergology, is when reactions occur to two or more different agents because they appear similar to the immune system.

CRP

CRP is the acronym for C-reactive protein; a nonspecific inflammatory marker protein produced by the liver and commonly measured in the blood. An elevated CRP in the blood is associated with infection, tumours, and inflammatory diseases.

Crust

Crust, when used in medicine, is dried body exudate. On the skin surface, a crust may be formed from dried serum, blood, or pus. Crust is also used in dermatopathology for a dry concretion of parakeratotic keratinocytes, serum, and inflammatory cells within the stratum corneum.

Crusted

Crusted is an adjective or verb pertaining to a crust or its formation. In dermatology, a rash may be described as having a crusted appearance or becomes crusted.

Crusting

Crusting is a verb which, when used in dermatology, is the formation of dried serum, blood or pus on the surface of the skin.

Cryoglobulin

Cryoglobulin is an immunoglobulin that precipitates out in the blood on exposure to cold.

Cryoglobulins

Cryoglobulins: plural of cryoglobulin; immunoglobulins that precipitate out in the blood on exposure to cold.

Cryotherapy

Cryotherapy is treatment using a very cold substance such as liquid nitrogen or dry ice. In dermatology, cryotherapy is often used to treat warts or actinic keratoses.

Crypt

Crypt is a chamber or room under the surface. So in dermatology, a crypt is a tube or recess extending down from the skin surface.

Cryptorchidism

Cryptorchidism is undescended testes (testicles).

Crypts

Crypts: plural of crypt; in dermatology, recesses or tubes extending down from the skin surface.

CT

CT is the acronym for computed tomography; a CT scan is a diagnostic radiology test that produces cross-sectional images of the body.

Cubital

Cubital is an adjective pertaining to the ulna bone in the forearm. The cubital (also called antecubital) fossa is the elbow crease anterior to (in front of) the elbow.

Culture

Culture is a noun and verb with many meanings, including: sociological, ie, the cultural practices or characteristics of a particular race or population; manners or taste, ie, to be cultured or refined; the artificial propagation of organisms, eg, a bacterial culture; a verb such as to culture a wound swab for bacteria.

Cumulative

Cumulative is an adjective pertaining to accumulation; describes increasing by successive additions.

Cutaneous

Cutaneous is an adjective pertaining to the skin.

Cuticle

Cuticle is the outermost layer of a hair, and is also the transparent layer of dead cells that connects the proximal nailfold to the nail plate.

Cutis

Cutis is the Latin word for skin.

Cyanosis

Cyanosis is the bluish colouration of the skin and mucous membranes due to deoxyhaemoglobin in the surface capillaries. This may be seen in either heart or lung disorders causing inadequate oxygenation, or when cold and the peripheral circulation is sluggish.

Cyclic

Cyclic: occurring in cycles, recurring regularly.

Cyclical

Cyclical: an adjective pertaining to a cycle; recurring.

Cynomolgus monkeys

Cynomolgus monkeys is the laboratory name for long-tailed or crab-eating macaques, Macaca fascicularis.

Cyrano nose

Cyrano nose has an enlarged tip, usually due to an infantile haemangioma. It is named for Cyrano de Bergerec, an historical figure said to have had a large nose.

Cyst

Cyst is a thin-walled closed capsule or sac-like structure, filled with fluid, solid or semisolid material. Cysts have an epithelial lining.

Cystic

Cystic is an adjective pertaining to a cyst, an enclosed space in a tissue containing fluid, solid or semi-solid material.

Cysts

Cysts: plural of cyst; thin-walled capsules containing fluid or semifluid material with an epithelial lining.

Cytogenetic

Cytogenetic is an adjective pertaining to cytogenetics, the study of chromosomes and their structure.

Cytogenetics

Cytogenetics is the study of chromosomes and their structure. It is a branch of cytology that specifically looks at the number and structure of chromosomes.

Cytokeratin

Cytokeratin is better known as keratin, a family of cytoplasmic proteins in epithelial cells.

Cytokeratins

Cytokeratins: plural of cytokeratin; better known as keratins, a family of cytoplasmic proteins in epithelial cells.

Cytokine

Cytokine is a low molecular-weight molecule that acts as an intercellular messenger. Interleukins, interferons, colony-stimulating factors, and chemokines are examples of specific types of cytokine.

Cytokines

Cytokines: plural of cytokine; low molecular-weight intercellular messengers.

Cytology

Cytology is the study of the structure and function of cells.

Cytopenic

Cytopenic: adjective pertaining to cytopenia, a reduction blood cell numbers.

Cytoplasm

Cytoplasm is the fluid inside a living cell.

Cytoplasmic

Cytoplasmic is an adjective pertaining to the cytoplasm of a cell, the fluid part of a living cell.

Cytotoxic

Cytotoxic is an adjective pertaining to cell-killing via toxins. Examples include cytotoxic drugs or cytotoxic lymphocytes.

Darier sign

Darier sign is positive when stroking the skin or lesion induces wealing; typically seen in cutaneous mastocystosis.

De novo

De novo is an adjective pertaining to new; in medicine it describes a condition that has occurred without a precursor.

De-novo

De-novo is an adjective pertaining to new; in medicine it describes a condition that has occurred without a precursor.

Debride

Debride is a verb meaning to remove infected or dead tissue to aid healing.

Debridement

Debridement is the process of removing infected or dead tissue to aid the healing process.

Debriding

Debriding is a form of the verb to debride, meaning to remove infected or dead tissue to aid the healing process.

Decompression

Decompression is the process of reducing the pressure of a gas.

Deform

Deform is a verb meaning to change the form, shape, or structure.

Deformities

Deformities: plural of deformity; malformations.

Deformity

Deformity is a malformation.

Degenerative

Degenerative is an adjective pertaining to loss of function or quality, eg, a degenerative disease.

Degranulation

Degranulation is the process by which cells release granules and their contents.

Demarcated

Demarcated is an adjective and verb to demarcate pertaining to separation or distinguishable. In dermatology it can refer to the boundary or division between two areas.

Demarcation

Demarcation is a noun meaning the boundary or plane of separation between two areas.

Dendrite

Dendrite is a long finger-like process of a cell that usually connects to another cell allowing direct intercellular passage of information or material.

Dendrites

Dendrites: plural of dendrite; long finger-like processes of cells that usually connect to other cells allowing direct intercellular passage of information or material.

Dendritic cell

Dendritic cell has long finger-like processes called dendrites. Examples of a dendritic cell include a neurone, melanocyte, Langerhans cell, and some types of tissue macrophage (immune cell).

Dendritic cells

Dendritic cells: plural of dendritic cell; cells with long finger-like processes (dendrites), and include neurones, melanocytes, Langerhans cells and some tissue macrophages (immune cells).

Deoxyribonucleic acid

Deoxyribonucleic acid (DNA) is a long double-helical molecule that can encode genes.

Dependent

Dependent is an adjective meaning to be subordinant or below in a relationship. In medicine it is used to describe a body part that is below the rest of the body, eg, normally the feet are dependent compared to the trunk.

Depigmentation

Depigmentation is the loss of skin pigment.

Deposition

Deposition is the process of depositing or the laying down of something. In the skin an example would be amyloid undergoing deposition. Deposition can also be used as a noun for the thing that is being deposited, eg, a deposition of amyloid.

Depositions

Depositions: plural of deposition; the things being laid down. An example is haemosiderin depositions in venous eczema.

Dermal

Dermal is an adjective pertaining to the skin, or more specifically to the dermis.

Dermal naevus

Dermal naevus (American spelling nevus) is a benign melanocytic naevus in which the melanocytes are entirely within the dermis. Dermal naevus is also called an intradermal naevus.

Dermatitis

Dermatitis is inflammation of the skin, but is mostly used more specifically as a synonym for eczema, ie, spongiotic inflammation of the epidermis.

Dermatologist

Dermatologist is a medical or surgical specialist in diseases of skin, hair, and nails. Refer to, What is a Dermatologist.

Dermatologists

Dermatologists: plural of dermatologist; medical or surgical specialists in diseases of the skin, hair, and nails.

Dermatology

Dermatology is the study of skin, hair and nails.

Dermatomal

Dermatomal is an adjective pertaining to a dermatome, an area of skin innervated by a single sensory spinal nerve, eg, shingles follows a dermatomal pattern.

Dermatome

Dermatome is the area of skin innervated by a single sensory spinal nerve. A dermatome is also a tool for taking fine slices of skin.

Dermatopathologist

Dermatopathologist is a medical specialist in the pathology of skin diseases.

Dermatopathologists

Dermatopathologists: plural of dermatopathologist; medical specialists in the pathology of skin diseases.

Dermatopathology

Dermatopathology is the study of the microscopic appearance of skin diseases.

Dermatoscope

Dermatoscope, also known as a dermoscope, is a handheld tool for examining the skin, nails, and hair, comprising a power source, light and magnification.

Dermatoscopic

Dermatoscopic is an adjective pertaining to the use of a dermatoscope (dermoscope); a handheld tool for examination of the skin, nails, and hair under magnification.

Dermatoscopy

Dermatoscopy, also called dermoscopy, is the use of a dermatoscope (dermoscope) to examine the skin, hair and nails.

Dermatoscopy or dermoscopy

Dermatoscopy refers to the use of a special magnifying device (a dermatoscope) to examine the skin, hair and nails.

Dermatoses

Dermatoses: plural of dermatosis; diseases of the skin.

Dermatosis

Dermatosis is a general term for any disease of the skin.

Dermis

Dermis is the fibrous layer of the skin immediately below the epidermis. This layer is composed predominantly of collagen but also elastin fibres which contribute to the pliability of the skin. The dermis also contains blood vessels, nerves, and adnexal structures including hair follicles, sweat, scent and sebaceous glands.

Dermopathies

Dermopathies: plural of dermopathy; diseases of the skin.

Dermopathy

Dermopathy is any disease of the skin. However it is also used in the names of specific skin diseases such as restrictive dermopathy.

Dermoscope

Dermoscope, also known as a dermatoscope, is a handheld tool for examining the skin, nails and hair, comprising a power source, light and magnification.

Dermoscopic

Dermoscopic is an adjective pertaining to the use of a dermoscope (dermatoscope); a handheld tool for examining the skin, nails, and hair under magnification.

Dermoscopy

Dermoscopy, also known as dermatoscopy, is the use of a dermoscope (dermatoscope) to examine the skin, nails, and hair under magnification.

Desensitisation

Desensitisation (American spelling desensitization) is a process of reversing a hypersensitivity reaction such as an allergy.

Desmoglein

Desmoglein is one of a family of molecules involved in forming desmosomes, the intercellular junctions that stick skin cells (keratinocytes) together. There are three main types of desmoglein in the skin.

Desmogleins

Desmogleins: plural of desmoglein; desmogleins are a family of molecules involved in forming desmosomes, the intercellular junctions that stick skin cells (keratinocytes) together. There are three main desmogleins in the skin.

Desmoplasia

Desmoplasia is a fibrous connective tissue reaction typically related to specific tumours.

Desmoplastic

Desmoplastic is an adjective used in histology pertaining to desmoplasia, the presence of a fibrous connective tissue reaction typically related to specific tumours.

Desmosome

Desmosome is a structure that holds adjacent epidermal skin cells (keratinocytes) tightly together, rather like cement between bricks.

Desmosomes

Desmosomes: plural of desmosome; the structures that hold adjacent epidermal skin cells (keratinocytes) tightly together, rather like cement between bricks.

Desquamation

Desquamation is the peeling of skin, coming off in scales, loss of squames.

Develop

Develop is a verb meaning to change, grow or progress over time.

Developing

Developing is an adjective and verb pertaining to development, the process of growth, change and evolution with time.

Development

Development is the process of growth or progress over time.

Developmental

Developmental is an adjective pertaining to development, the process of growth or progress over time.

Dexterity

Dexterity is the skill of using the hands.

Dialysis

Dialysis is a process using a membrane to separate particles in a liquid based on size. In medicine this process can be used to remove waste products and fluid from the body, eg, dialysis for renal failure can be by haemodialysis or peritoneal dialysis.

Diascopy

Diascopy is a test using pressure from clear glass or plastic to see if a rash or lesion blanches. Diascopy also allows assessment of the underlying colour.

Differential diagnosis

Differential diagnosis is a list of conditions with similar symptoms or signs needed to be considered as possibie diagnoses.

Differentiated

Differentiated is a past tense of the verb to differentiate, to make a distinction. It can also be used as an adjective, for example, well-differentiated tumour cells closely resemble normal cells from that tissue, compared to poorly differentiated meaning no longer resembles its parent cell/tissue.

Differentiation

Differentiation is the process of making different. In the skin the differentiation of a cell is the process of maturation and specialisation.

Diffuse

Diffuse is an adjective and verb pertaining to spread over a wide area. In dermatology, diffuse is used as an adjective to describe a change that is not localised or patchy, eg, diffuse alopecia compared to patchy alopecia.

Digit

Digit is a finger or toe.

Digits

Digits: plural of digit; fingers and toes.

Diploid

Diploid is an adjective describing a cell having two sets of chromosomes, as is typically seen in a normal somatic cell.

Discharge

Discharge is a verb and noun pertaining to emergence, exit or flow out, eg, to discharge a patient from hospital; and a secretion or excretion emerging from the body., such as a vaginal discharge.

Discoid

Discoid is an adjective to describe being round like a disk. In dermatology it is used to describe lesions that are circular or oval and often well-defined, eg, discoid eczema and discoid lupus.

Discrete

Discrete is an adjective to describe being separate or distinct. For example, a discrete lesion is separated from other lesions by normal skin.

Disseminate

Disseminate is a verb to scatter or distribute widely.

Disseminated

Disseminated is an adjective to describe being scattered or widespread and derives from the verb to disseminate meaning to scatter. Disseminated is therefore also the past tense of the verb. Examples in dermatology may include an infection that gained entry through the skin disseminated throughout the body; a rash may present as disseminated lesions distributed/scattered widely over most of the body surface.

Distal

Distal is an adjective to describe being furthest from the point of origin or closest to the end. Anatomically this may mean being furthest from the centre of the body.

Distribution

Distribution is the localisation or pattern. The distribution of a dermatosis refers to the pattern or localisation of skin lesions, and can be quite characteristic for a specific condition.

DLQI

DLQI is the acronym for Dermatology Life Quality Index, a tool used for assement of the impact of a skin disease on the patient.

DNA

DNA is the acronym for deoxyribonucleic acid, a long nucleic acid chain that can encode genes, the famous double helix.

Dolichocilia

Dolichocilia is unusually long eyelashes.

Dorsal

Dorsal is an adjective pertaining to the back or posterior part. A dorsal location means on the upper surface or back of a body part.

Dorsum

Dorsum is a noun used in anatomy to mean the back, eg, the back of the trunk or the back of a hand.

Double-blind

Double-blind is an adjective used to describe clinical trials in which neither the participants nor the researchers know which treatment or intervention has been selected for the individual, ie, both the assessor and the participant are blinded to the intervention.

Duplex ultrasonography

Duplex ultrasonography combines two types of ultrasound to produce a scan of blood flow in arteries and veins.Traditional ultrasonography scans a fixed object (ie, the artery or vein) and is combined with a Doppler scan of moving objects (ie, blood flow). Uses of duplex ultrasonography include identification of a DVT, incompetent valves in varicose veins, or to map out vessels for sclerotherapy.

Duplex ultrasound

Duplex ultrasound is an imaging test combining two types of ultrasound to produce a scan of blood flow in arteries and veins. Traditional ultrasound scans a fixed object (ie, the artery or vein), and is combined with a Doppler scan of moving objects (ie, blood flow). Uses for duplex ultrasonography scan include identification of a DVT, incompetent valves in varicose veins, or to map out vessels for sclerotherapy.

Duplex-ultrasound scan

Duplex-ultrasound scan combines two types of ultrasound to produce a scan of blood flow in arteries and veins. Traditional ultrasound scans a fixed object (ie, the artery or vein), and is combined with a Doppler scan of moving objects (ie, blood flow). Uses for duplex ultrasonography scan include identification of a DVT, incompetent valves in varicose veins, or to map out vessels for sclerotherapy.

Dysaesthesia

Dysaesthesia (American spelling dysesthesia) literally means abnormal (dys) sensation (aesthesia) and describes unpleasant, uncomfortable sensations produced by ordinary stimuli. There are many specific types of dysaesthesia, eg, orodynia, pruritus ani, brachioradial pruritus, male genital dysaesthesia, etc.

Dysbacteriosis

Dysbacteriosis, also called dysbiosis, is an imbalance in the microbial community (microbiome) of a specific body site, eg, the skin, vagina, bowel.

Dysbiosis

Dysbiosis, also called dysbacteriosis, is an imbalance in the microbial community (microbiome) of a specific body site, eg, the skin, vagina, bowel.

Dysfunction

Dysfunction is malfunction, an abnormal function.

Dysfunctional

Dysfunctional is an adjective pertaining to dysfunction, an abnormal or malfunctioning state or situation.

Dysgeusia

Dysgeusia is abnormal or disturbed sense of taste.

Dyskeratosis

Dyskeratosis is a histological term for premature or altered (abnormal) keratinocyte differentiation.

Dyskeratotic

Dyskeratotic is an adjective used in histology pertaining to dyskeratosis; premature or abnormal keratinisation of cells in the epidermis.

Dyslipidaemia

Dyslipidaemia (American spelling dyslipidemia) is an abnormally high level of one or more lipids or lipoproteins in the bloodstream.

Dysmorphia

Dysmorphia is a deformity or abnormality in shape or size of a body part.

Dysmorphic

Dysmorphic is an adjective pertaining to an anatomical malformation.

Dyspareunia

Dyspareunia is the medical term for painful sexual intercourse.

Dysphagia

Dysphagia is difficulty in swallowing.

Dyspigmentation

Dyspigmentation is any abnormality in the distribution of pigment in the skin.

Dysplasia

Dysplasia is the abnormal growth or development of cells or organs.

Dysplastic

Dysplastic is an adjective pertaining to dysplasia, abnormal or atypical appearance of a cell or tissue.

Dysregulate

Dysregulate is a verb meaning to inhibit or prevent a controlling mechanism. It is used in medicine to mean the inhibition or prevention of a physiological control.

Dysregulated

Dysregulated is the past tense of the verb to dysregulate, meaning to inhibit or prevent a controlling mechanism. In medicine it is used when there has been an abnormality or impairment of a physiological control. A process has been dysregulated.

Dysregulation

Dysregulation is the failure to control or regulate a physiological mechanism or process.

Dysrhythmia

Dysrhythmia: an irregular heart beat.

Dysrhythmias

Dysrhythmias: plural of dysrhythmia, an irregular heart beat.

Dystonia

Dystonia refers to uncontrollable muscle contractions and movements. Dystonia be localised to one muscle group or generalised to the entire body.

Dystrophic

Dystrophic is an adjective pertaining to dystrophy, a weakening or degeneration of a tissue.

Dystrophy

Dystrophy refers to degeneration or abnormal formation of tissue due to disease or malnutrition. A well-known example is muscular dytrophy caused by a genetic mutation. An example in dermatology is nail dystrophy, meaning a nail that did not develop normally or has become abnormal due to a disease such as tinea.

Dysuria

Dysuria is a burning painful sensation when passing urine.

EASI

EASI is the acronym for Eczema Area and Severity Index, a tool used for assessment and monitoring of atopic eczema.

Ecchymoses

Ecchymoses: plural of ecchymosis; bruises; large purpura; discolourations due to bleeding under the skin.

Ecchymosis

Ecchymosis is a bruise; a discolouration due to bleeding under the skin.

Eccrine

Eccrine is an adjective derived from the Greek to secrete.

Eccrine gland

Eccrine gland is the common sweat gland in the skin.

Eccrine glands

Eccrine glands: plural of eccrine gland; the common sweat glands found deep in the dermis.

ECG

ECG (American terminology EKG) is the acronym for electrocardiogram; graph of the electrical activity of the heart.

Echocardiogram

Echocardiogram ('echo' for short) uses ultrasound waves to produce a live video of the heart to assess size, muscle and valve function. The most common type of echocardiogram is done through the chest wall (transthoracic) using a transducer applied to the skin of the chest. A stress echocardiogram assesses heart function before and again after excercise when the heart is pumping harder. The third type is called a transoesophageal echocardiogram.

Echocardiograms

Echocardiograms: plural of echocardiogram; use ultrasound waves to produce live videos of the heart to assess size, muscle and valve function. Echocardiograms come in three types: transthoracic, transoesophageal, and stress test.

Eclabion

Eclabion: plural of eclabium; turning out of the lips.

Eclabium

Eclabium is a turned-out lip; eversion of a lip.

Ectasia

Ectasia is a widening or dilation of a tube-like structure such as a blood vessel.

Ectodermal

Ectodermal is an adjective pertaining to the ectoderm. An example is ectodermal dysplasia. The ectoderm is the outermost of the three primary germ layers of an embryo (the other two being mesoderm and endoderm). Ectoderm develops into epidermis and neural tissue.

Ectopic

Ectopic is an adjective pertaining to not being in the right place, eg, an ectopic pregnancy has developed somewhere other than inside the uterus.

Ectropion

Ectropion is a turned out part. Common usage has ectropion meaning the eversion (turning out) of a lower eyelid resulting in exposure of the inside surface of the eyelid.

Eczema

Eczema, also called dermatitis, is an inflammatory condition of the skin defined histologically by the presence of epidermal spongiosis.

Eczematous

Eczematous is an adjective pertaining to eczema, resembling eczema, being eczema-like.

Efficacy

Efficacy is a noun for achieving a desired effect, eg, the efficacy of a treatment.

Effluvium

Effluvium, when used in dermatology, refers to diffuse hair loss of various causes. In general usage, an effluvium is an unpleasant gaseous smell.

Elastic fibre

Elastic fibre (American spelling fiber) is composed of elastin and microfibrils of fibrillin, collagen VI, and other proteins and glycoproteins. An elastic fibre demonstrates elasticity, the ability to stretch and return to the original.

Elastic fibres

Elastic fibres: plural of elastic fibre (American spelling fibers/fiber); are composed of elastin and microfibrils of fibrillin, collagen VI and other proteins and glycoproteins. Elastic fibres form a meshwork to provide elasticity in the dermis, arterial walls, and the back of the eye.

Elastin

Elastin is one of the proteins making up elastic fibres. Elastin is probably produced by fibroblasts.

Elastolysis

Elastolysis is a histological term used to describe the loss or destruction of connective tissue elastic fibres.

Elastolytic

Elastolytic is an adjective pertaining to elastolysis, the breakdown and loss of elastic fibres.

Elastoma

Elastoma is a variant of connective tissue naevus; a congenital hamartoma characterised by increased elastic fibres.

Elastomas

Elastomas: plural of elastoma; congenital hamartomas composed of increased elastic fibres.

Elastosis

Elastosis is a histological term for an increase in the elastic fibres in the skin.

Elastotic

Elastotic is an adjective used in histology pertaining to elastic tissue and fibres. Due to observed histological changes, elastotic often finds its way into the name of the condition as well.

Electrocardiogram

Electrocardiogram (ECG, American terminology EKG)) is a graph of the electrical activity of the heart.

Electrocardiography

Electrocardiography is the process of performing an electrocardiogram, a graph of the electrical activity of the heart.

Electron microscopy

Electron microscopy is a laboratory tool used to examine extremely thin specimens with a beam of electrons passed through an electromagnetic lens. Electron microscopy allows visualisation of much smaller structures than light microscopy.

Electrophoresis

Electrophoresis is a laboratory technique to separate molecules by their electric charge and size using an electric field.

Emboli

Emboli: plural of embolus; small particles carried through the bloodstream to block small blood vessels. Examples include air bubbles, blood clots, and clumps of bacteria.

Embolic

Embolic is an adjective pertaining to an embolus (emboli), small piece(s) of foreign material in a blood vessel causing a blockage.

Embolisation

Embolisation is the process of forming an embolus, typically blocking a blood vessel. Embolisation can be a pathological process such as occurs in a pulmonary embolus, or may be a medical procedure to block or close off abnormal vessels.

Embolism

Embolism is the obstruction of a blood vessel(s) by an embolus/emboli, small piece(s) of a foreign material.

Embolisms

Embolisms: plural of embolism; blockages of blood vessels by small pieces of foreign material.

Embolus

Embolus is a small particle that has been carried through the bloodstream and blocks a small blood vessel. The particle is foreign to the bloodstream and examples include an air bubble, fat, clump of bacteria, or blood clot.

Emollient

Emollient derives from the Latin to soften, so an emollent is a moisturiser that softens the skin.

Emollients

Emollients: plural of emollient; moisturisers that soften the skin.

Enanthem

Enanthem, also called an enanthema, is a rash on mucous membranes.

Enanthema

Enanthema, also called an enanthem, is a rash occurring on mucous membranes.

Enanthemata

Enanthemata: plural of enanthem; rashes on mucous membranes.

Enanthems

Enanthems, plural of enanthem(a), rashes on the mucous membranes, usually due to a viral infection.

Encapsulated

Encapsulated is an adjective and verb pertaining to being within a capsule. A medication may be encapsulated, ie, in a capsule form rather than a tablet. In histology encapsulated describes a pathological process being contained by a membrane or wall, eg, a cyst is encapsulated by the fibrous wall. Microorganisms can also be encapsulated by a protective thick mucoid or polysaccharide layer.

Encephalitis

Encephalitis is inflammation of the brain.

Encephalopathy

Encephalopathy is a general term covering a range of temporary or permanent disorders of brain function, including those caused by toxins or infections.

Encysted

Encysted: past tense of the verb to encyst; pertains to enclosed walled-off stage of primitive organisms such as protozoa; often inactive.

Endemic

Endemic is an adjective used to describe being constantly present in a population or region, eg, an endemic disease may be due to an infectious organism or arthropod that spreads an infection occurring in an area due to climatic factors.

Endocarditis

Endocarditis is inflammation of the heart valves and lining of the heart muscle.

Endocrine

Endocrine is an adjective pertaining to the production and release of secretions (hormones) directly into the blood.

Endocrinological

Endocrinological is an adjective pertaining to hormones or the hormone (endocrine) system.

Endocrinologist

Endocrinologist is a medical specialist in diseases of the endocrine (hormone) system.

Endocrinologists

Endocrinologists: plural of endocrinologist; medical specialists in diseases of the endocrine (hormone) system.

Endocrinopathies

Endocrinopathies: plural of endocrinopathy; diseases of the endocrine system; hormonal problems.

Endocrinopathy

Endocrinopathy is a disease of the endocrine system; a hormonal problem.

Endogenous

Endogenous is an adjective to describe an origin from within. In medicine an endogenous cause for an illness means it has not been caused by an external agent or event, eg, atopic dermatitis is an example of an endogenous form of eczema.

Endoscope

Endoscope is an instrument introduced into a body cavity or organ to allow visual examination.

Endoscopic

Endoscopic is an adjective pertaining to the use of an endoscope, an instrument introduced into a body cavity or organ to allow direct visual examination.

Endoscopy

Endoscopy is the use of an endoscope, an instrument introduced into a body cavity or organ allowing direct visual examination.

Endothelial

Endothelial is an adjective pertaining to cells derived from the embryonal mesoderm to form the endothelium lining blood vessels and heart cavities, eg, endothelial cells.

Endothelium

Endothelium is the layer of cells that line the blood vessels and the heart.

Endovenous

Endovenous is an adjective to describe being inside a vein.

Entheses

Entheses: plural of enthesis; connections between ligaments or tendons and bones.

Enthesis

Enthesis is the connection between a tendon or ligament and bone.

Enthesitis

Enthesitis is inflammation of an enthesis, the connection between a tendon or ligament and bone.

Enthesopathy

Enthesopathy is any condition affecting an enthesis, where a tendon or ligament attaches to bone.

Enzymatic

Enzymatic is an adjective pertaining to enzymes; biological catalysts.

Enzyme

Enzyme is a biological catalyst involved in biochemical reactions.

Enzymes

Enzymes: plural of enzyme; biological catalysts involved in biochemical reactions.

Eosinophil

Eosinophil is a type of granulocytic white blood cell (granular leukocyte) involved in the innate immune system primarily as defence against parasitic infections. Eosinophils are pro-inflammatory and are found in large numbers in allergic inflammation.

Eosinophilia

Eosinophilia is an increase in the number of eosinophils in the peripheral blood.

Eosinophilic

Eosinophilic is an adjective pertaining to staining red with the dye eosin on microscopy. Examples include the eosinophilic cytoplasmic granules seen in eosinophils, the eosinophilic stratum corneum of the epidermis, and normal eosinophilic collagen fibres in the dermis.

Eosinophils

Eosinophils: plural of eosinophil; granulocytic leukocytes with cytoplasmic granules which stain red with eosin.

Ephilides

Ephilides: plural of ephelis; freckles.

Ephilis

Ephilis is a freckle.

Epicanthic fold

Epicanthic fold is the skin fold of the upper eyelid that covers the inner corner of the eye.

Epicanthic folds

Epicanthic folds: plural of epicanthic fold; the skin folds of the upper eyelids that cover the inner corners of the eyes.

Epidemic

Epidemic is the sudden occurrence of a disease (or other event) in excess of that normally expected. Epidemic can be used as a noun or adjective, eg, a 'flu epidemic or epidemic typhus.

Epidemics

Epidemics: plural of epidemic; sudden occurrence of diseases or other events in excess of that normally expected, eg, 'flu epidemics.

Epidemiological

Epidemiological is an adjective pertaining to epidemiology, the study of population health.

Epidemiology

Epidemiology is the study of the distribution of a disease and factors involved in the spread of that disease in populations.

Epidermal

Epidermal is an adjective pertaining to the epidermis, the outermost layer of the skin, eg, epidermal naevus.

Epidermis

Epidermis is the outer epithelial layer of the skin overlying in the dermis. It is mainly composed of keratinocytes, but also includes melanocytes, Merkel cells and other cell types in small numbers.

Epidermolytic

Epidermolytic is an adjective used in histology to describe loosening of the epidermis.

Epidermotropism

Epidermotropism is movement into or towards the epidermis. It is a histological term for the migration of cells into the epidermis typically seen in mycosis fungoides and Paget disease.

Epididymis

Epididymis is the long coiled tube connecting the testis to the urethra, which stores and transports sperm in the male. It is located in the scrotum on the back of each testis.

Epigenetic

Epigenetic is an adjective pertaining to gene expression unrelated to the genetic code itself but affected by modification such as DNA methylation.

Epigenetics

Epigenetics is the study of phenotypic change due to changes in gene expression without changes in the gene itself. An example is modification of DNA methylation.

Epinephrine

Epinephrine (British terminology adrenaline) is a hormone made in the adrenal gland, a neurotransmitter, and a drug.

Epiphyseal

Epiphyseal is an adjective relating to the epiphysis, the part of a long bone where growth occurs, eg, epiphyseal plate, epiphyseal closure.

Epistaxis

Epistaxis is bleeding from the nose.

Epithelial

Epithelial is an adjective pertaining to epithelium, the tissues forming the outer layer of the body, such as skin and linings of the respiratory, gastrointestinal, and genitourinary tracts, eg, epithelial hyperplasia.

Epithelioid

Epithelioid is an adjective used in histology to describe a resemblance to epithelium.

Epithelioid cell

Epithelioid cell is large and round with abundant eosinophilic cytoplasm, prominent vesicular nucleus, and large nucleolus.

Epithelioid cells

Epithelioid cells: plural of epithelioid cell; large round cells with abundant eosinophilic cytoplasm, prominent vesicular nuclei, and large nucleoli.

Epithelioma

Epithelioma is a benign or malignant tumour arising from epithelial cells.

Epitheliomas

Epitheliomas: plural of epithelioma; malignant or benign tumours arising from epithelium.

Epithelium

Epithelium is the thin layer that lines the body surface both externally (ie, skin), and internally (ie, mucous membranes).

Eponychium

Eponychium is the nail cuticle, the skin attaching the proximal nail-fold to the nail-plate.

Erosion

Erosion is the superficial or partial destruction of a surface such as skin, that does not scar on healing.

Erosions

Erosions: plural of erosion; multiple areas of superficial or partial destruction of a surface such as the skin.

Erosive

Erosive is an adjective pertaining to erosion, the superficial or partial destruction of a surface such as the skin.

Eruption

Eruption is a sudden appearance, explosion, outbreak. Multiple lesions on the skin that have appeared suddenly is a skin eruption.

Eruptions

Eruptions: plural of eruption; multiple lesions on the skin that appeared suddenly. It can be used either to mean multiple episodes or multiple forms of a particular eruption type.

Erythema

Erythema means red, and in dermatology it describes skin reddened by increased blood supply.

Erythematous

Erythematous is an adjective describing a red colour, eg, skin is erythematous due to increased flow of blood.

Erythrocyte

Erythrocyte is a red blood cell. These cells carry oxygen through the bloodstream to the tissues in the body.

Erythrocyte sedimentation rate

Erythrocyte sedimentation rate (acronym ESR) is a test of blood viscosity. The ESR is a nonspecific test often raised in inflammatory diseases and infections.

Erythrocytes

Erythrocytes: plural of erythrocyte; red blood cells. Erythrocytes carry oxygen through the bloodstream to the tissues in the body.

Erythrocytosis

Erythrocytosis is an abnormal increase in circulating red blood cell mass.

Erythroderma

Erythroderma is defined as redness affecting at least 90% of the skin surface.

Eschar

Eschar is a full thickness scab that develops in a healing wound. Examples include wounds caused by a thermal burn, cauterisation, or chemical burn. An eschar can be typical of some infections particularly rickettsia.

Eschars

Eschars: plural of eschar; full thickness scabs that develop in a healing wound, for example after a thermal burn or a cauterisation.

ESR

ESR is the acronym for erythrocyte sedimentation rate, a test of blood viscosity. The ESR is a nonspecific test often raised in inflammatory diseases and infections.

Euglycaemia

Euglycaemia (American spelling euglycemia) is the state of normal blood sugar (glucose) level.

Eukaryote

Eukaryote is a cellular organism in which the genetic material is contained within a nucleus.

Exacerbate

Exacerbate is a verb meaning to make worse or aggravate.

Exacerbates

Exacerbates is a form of the verb to exacerbate, meaning worsens or aggravates.

Exacerbating

Exacerbating is an adjective pertaining to exacerbation, an aggravation or worsening.

Exacerbation

Exacerbation is a noun meaning an aggravation, worsening, or flare up.

Exacerbations

Exacerbations: plural of exacerbation; aggravations, flares.

Exanthem

Exanthem is a widespread skin rash typically caused by a drug or infection, usually accompanied by systemic symptoms such as fever, malaise, and headache.

Exanthematous

Exanthematous is an adjective pertaining to an exanthem, a widespread rash associated with systemic symptoms often viral or drug in origin.

Excipient

Excipient is an additive to an active drug for medical use. Examples of an exipient include the vehicle or base of a topical preparation, preservative, colouring agent and flavouring.

Excipients

Excipients: plural of excipient; additives to an active drug for medical use including the vehicle or base of a topical preparation, preservatives, colouring agents and flavourings.

Excision

Excision is the surgical removal of an entity such as an organ, tumour, lesion, or foreign body.

Excisional biopsies

Excisional biopsies: plural of excisional biopsy; the complete surgical removal of lesions for diagnosis, treatment, or both.

Excisional biopsy

Excisional biopsy is the complete surgical removal of a lesion for diagnosis, treatment or both.

Excisions

Excisions: plural of excision; surgical removals of tissues, lesions, or organs.

Excoriation

Excoriation, also called a scratch mark, is a loss of epidermis and a portion of the dermis due to scratching. An excoriation may be linear or punctate.

Excoriations

Excoriations: plural of excoriation; scratch marks; the loss of epidermis and some of the dermis due to scratching. Excoriations may be linear or punctate.

Exfoliation

Exfoliation is the process of peeling or shedding of the epidermal stratum corneum. It may occur after skin inflammation, or be induced by chemicals or abrasion.

Exfoliative

Exfoliative is an adjective pertaining to exfoliation, the peeling off in scales or layers.

Exocytosis

Exocytosis is a histological term for the random migration of inflammatory cells, such as lymphocytes, neutrophils, basophils, into the epidermis. Exocytosis is induced by cytokine release in inflammatory processes of the epidermis.

Exogenous

Exogenous is an adjective pertaining to an outside influence or cause. In medicine an exogenous cause for an illness means the cause is not from within, eg, contact dermatitis is an example of an exogenous form of eczema.

Exostosis

Exostosis is a benign growth of new bone out of existing bone.

Exotoxin

Exotoxin is a toxin (poison) produced by and released from a living organism into the surrounds.

Exotoxins

Exotoxins: plural of exotoxin; toxins (poisons) produced by and released from living organisms into the surrounds.

Exposed skin

Exposed skin is skin bared to or influenced by contact with external agents such as sun, chemical allergens, irritants, or physical agents.

Exposed to environment

Exposed to the environment results in potential contact with external agents such as sun, wind, water, irritants and allergens.

Extemporaneous

Extemporaneous is an adjective to describe without prior preparation, being prepared or mixed at the time of dispensing in the case of a medication.

Extemporaneously

Extemporaneously is an adverb meaning carried out without prior preparation; when applied to medicines it means they are prepared or mixed at the time of dispensing.

Extensor

Extensor can be used as an noun or adjective. An extensor is a muscle that extends a joint, and the adjective pertains to these muscles. Extensor aspect overlies extensor muscles.

External auditory canal

External auditory canal connects the outside of the head to the eardrum.

External beam radiotherapy

External beam radiotherapy is the most common form of radiation treatment in which high-energy radiation is directed from outside the body onto an internal cancer.

External-beam radiotherapy

External-beam radiotherapy is the most common form of radiation treatment in which high-energy radiation is directed from outside the body onto an internal cancer.

Extra-articular

Extra-articular is an adjective meaning outside or away from a joint, eg, an extra-articular manifestation.

Extraarticular

Extraarticular is an adjective pertaining to the outside of or away from a joint.

Extracellular matrix

Extracellular matrix is the meshwork or scaffold of molecules outside the cells of a tissue that provides support to those cells. Collagen and elastic fibres are major components of the dermal extracellular matrix.

Extracutaneous

Extracutaneous is an adjective meaning other than or away from the skin, eg, involvement of extracutaneous sites or organs.

Extranodal

Extranodal is an adjective meaning other than lymph nodes, mostly used to mean involvement of other sites with lymphoma.

Extrapulmonary

Extrapulmonary is an adjective meaning to be outside of, not involving, the lungs

Extrapyramidal

Extrapyramidal: is an adjective pertaining to a system that controls motor function.

Extravasate

Extravasate is a verb meaning to leak from a blood vessel into body tissue.

Extravasated

Extravasated is an adjective and past tense verb related to leakage from a blood vessel into body tissue.

Extravasation

Extravasation is the leakage of fluid or cells from a blood vessel into body tissue, eg, extravsation of red blood cells results in a bruise.

Exudate

Exudate is the ooze typically seen in wounds, derived from blood, and composed of protein and blood cells. An exudate can be described as serous, purulent, sanguinous or serosanguinous.

Exudates

Exudates: plural of exudate; oozing and exuded matter from wounds, erosions or ruptured blisters.

Facies

Facies is the appearance of the face, which can sometimes be characteristic or aid in the diagnosis of a disorder.

Familial

Familial is an adjective pertaining to family. Familial conditions occur in two or more members of a family and may be genetic or environmental in origin. Genodermatoses may include 'familial' in the name of the condition, eg, familial benign chronic pemphigus.

Fascia

Fascia is collagen-based soft tissue in the body. It is classified as superficial, deep, visceral, and parietal. Fascia encloses and separates compartments and organs, stablises and attaches tissues. The superficial fascia is variably defined as all that lies below the epidermis, or only that part below the subcutaneous fat.

Fascicle

Fascicle is a bundle of fibres or structures such as a bundle of nerve or muscle fibres.

Fascicles

Fascicles: plural of fascicle; when used in biology fascicles are bundles of fibres or structures such as nerves or muscles.

Febrile

Febrile is an adjective pertaining to a fever.

Felon

Felon is a painful abscess in the pulp of a finger or toe.

Ferritin

Ferritin is a body protein that stores iron. Blood ferritin levels are measured to indicate body iron stores.

Fever

Fever is an abnormally high body temperature, usually defined as being over 38 C (100.4 F). It may be accompanied by shivering, headache, and in severe instances, delirium.

Fibril

Fibril is a small fibre or filament.

Fibrils

Fibrils: plural of fibril; small fibres or filaments.

Fibrin

Fibrin is a non-globular insoluble protein formed from fibrinogen, and polymerises to form a blood clot.

Fibrinogen

Fibrinogen is a globulin protein that is the precursor to fibrin. Fibrinogen is cleaved by thrombin to release the fibrin monomer which then polymerises to form a blood clot.

Fibrinoid

Fibrinoid is an adjective meaning fibrin-like. Fibrinoid is used in histology to describe eosinophilic structureless deposits that resemble fibrin, eg, fibrinoid necrosis.

Fibrinoid necrosis

Fibrinoid necrosis is cell death induced by vascular damage from the formation of immune complexes.

Fibroblast

Fibroblast is the most numerous cell type seen in loose connective tissue. In the dermis, fibroblasts produce collagen, elastin, ground substance, and fibronectin.

Fibroblasts

Fibroblasts: plural of fibroblast; the most numerous cell type seen in loose connective tissue. In the dermis fibroblasts produce collagen, elastin, ground substance and fibronectin.

Fibroepithelial

Fibroepithelial is an adjective used to describe the combination of fibrous tissue and epithelium seen on histology.

Fibroepithelioma

Fibroepithelioma is a tumour characterised histologically by fibrous tissue and strands of basal cells in the dermis. It is more correctly called a fibroepithelioma of Pinkus, regarded as being either a rare form of basal cell carcinoma, or a premalignant lesion.

Fibroma

Fibroma describes a family of benign tumours characterised by an increased collagenous stroma. Most present as solitary or multiple dome-shaped skin-coloured papules or nodules.

Fibromas

Fibromas: plural of fibroma; benign tumours consisting mainly of fibrous tissue.

Fibromyalgia

Fibromyalgia is a chronic disease causing stiffness and pain of muscles and joints in the absence of inflammation.

Fibronectin

Fibronectin is a glycoprotein that comes in two forms; circulating (made in the liver) and tissue (made by fibroblasts and endothelial cells). It has many roles particularly in inflammation and wound healing.

Fibroplasia

Fibroplasia is a word used in histology for the growth of fibrous tissue.

Fibrosing

Fibrosing is an adjective and verb pertaining to fibrosis, the formation of fibrous connective tissue.

Fibrosis

Fibrosis is the formation of fibrous connective tissue, either as a normal repair (scarring) or in excess in a pathological process.

Fibrotic

Fibrotic is an adjective describing the presence of excessive fibrous tissue; in the skin this feels leathery, bound-down, thickened or scarred.

Filament

Filament is a thread-like structure or fibre.

Filiform

Filiform is an adjective pertaining to filament, a thread-like structure, eg, filiform wart or filiform papilla of the tongue.

First degree relative

First degree relative: parent, sibling, or child.

FISH

FISH is the acronym for fluorescent in situ (in-situ) hybridisation, a cytogenetic test used to detect chromosomal abnormalities.

Fissure

Fissure is a noun and verb pertaining to a split or crack. In the skin a fissure may present as an erosion or narrow ulceration; the skin may fissure to form a split.

Fissured

Fissured is an adjective and verb pertaining to being split, torn or cracked, eg, fissured skin; the skin fissured.

Fissures

Fissures: plural of fissure; splits, cracks, grooves, clefts.

Fissuring

Fissuring is from the verb to fissure, meaning to split or crack.

Fistula

Fistula is an abnormal passage between two surfaces, two hollow cavities, or a hollow cavity to the body surface.

Fistulae

Fistulae: plural of fistula; abnormal passages between two surfaces, two hollow cavities, or a hollow cavity to the body surface.

Fistulas

Fistulas: plural of fistula; abnormal passages between two surfaces, two hollow cavities, or a hollow cavity to the body surface.

Flaccid

Flaccid is an adjective used to describe hanging loosely, not firm or tense. In dermatology is it typically used to describe a loose blister.

Flexion

Flexion is a bending movement that reduces the angle across a joint.

Flexor

Flexor is an adjective pertaining to flexion, the folding of the body, often at a joint eg, a flexor muscle bends a limb or digit at a joint; a flexor surface is that surface on the inside of the fold or bend. Common usage has flexor as a noun, a muscle that bends a limb at the joint.

Flexural

Flexural is an adjective relating to a bend or fold. In the skin the backs of knees (popliteal fossae), the armpits (axillae), the antecubital (cubital) fossae and the groin are examples of flexural sites. Atopic dermatitis is described as having a flexural distribution on the limbs as it commonly involves the popliteal and antecubital (cubital) fossae.

Flexure

Flexure is a bend or fold, eg, a skin flexure is a skin fold where skin comes in contact across that fold.

Flexures

Flexures: plural of flexure; bends or folds. Skin flexures include under the breasts, armpits, cubital fossae, groin, behind the knees, and describe sites where skin comes in contact across that fold or bend.

Florid

Florid is an adjective used either to describe bright red skin or a fully developed condition, eg, a florid complexion; a florid rash.

Fluctuance

Fluctuance is a noun indicating the presence of fluid in a confined space. Fluctuance is a sign that can be elicted.

Fluctuant

Fluctuant is an adjective pertaining to fluctuance, wave-like rising and falling usually in relation to fluids. In medicine it is used to describe the movement of fluids in the body, eg, describing a mass or tumour as being fluctuant means it is fluid-filled.

Fluorophore

Fluorophore, also called a fluorochrome, is a fluorescent chemical or dye.

Fluorophores

Fluorophores: plural of fluorophore; fluorescent chemicals.

Focal

Focal is an adjective pertaining to focus, relating to or having a focus. It is generally used in medicine to mean being localised to a specific area or tissue.

Follicle

Follicle is a noun with multiple meanings in medicine, including related to the ovary (and follicle stimulating hormone) and lymphocytes (eg, primary cutaneous follicle centre lymphoma). In the skin, a hair follicle is the tubular cavity within which a hair grows.

Follicles

Follicles: plural of follicle; multiple meanings in medicine including relating to structures in the ovaries, lymph nodes, and skin.

Follicular

Follicular is an adjective pertaining to a follicle. In dermatology this usually means a hair follicle, eg, a follicular lesion is located within or around a hair follicle. However in histology follicular also pertains to lymphoid follicles and ovarian follicles.

Formulate

Formulate is a verb meaning to develop a plan, process, or recipe.

Formulation

Formulation is the process of preparing or mixing according to a formula (recipe). Formulation can also be used as the noun for the end product of such a process.

Formulations

Formulations: plural of formulation; the resultant products after preparation or mixing according to formulas (recipes).

Fraction

Fraction is a small part or amount of something whole.

Fractionate

Fractionate is the verb to divide something into smaller parts or amounts.

Fractionated

Fractionated is a verb related to having divided or separated into smaller parts or amounts.

Fragility

Fragility is a noun meaning being easily broken or damaged. Fragility of the skin is the easy bruising and tearing seen especially in the elderly.

Free radical

Free radical is an unstable form of an atom with an unpaired electron, for example, a reactive oxygen species.

Free radicals

Free radicals; plural of free radical; unstable forms of atoms with an unpaired electron, for example, reactive oxygen species. Free radicals can damage cells and tissues.

Frontotemporal

Frontotemporal is an adjective pertaining to the frontal and temporal bones of the skull. For example in surface anatomy, frontotemporal refers to the forehead and temples.

Fundus

Fundus of an organ is the point furthest away from the organ opening or exit, eg, the fundus of the eye is the back of the interior of the eye opposite the pupil.

Fungating

Fungating is an adjective pertaining to a fungus. In dermatology, it is typically used to describe a tumour erupting like a mushroom or toadstool.

Furfuraceous

Furfuraceous is an adjective pertaining to bran. In dermatology, it is used to describe fine skin scale which is bran-like or powdery.

Galenical

Galenical is a medicine prepared from plants.

Gamete

Gamete is a haploid cell (having one copy of each chromosome instead of two) for sexual reproduction. In the female this is an ovum (egg) produced in the ovaries, and in the male, sperm produced in the testes (testicles).

Gametes

Gametes: plural of gamete; ova in females and sperm in males for sexual reproduction.

Gammopathies

Gammopathies: plural of gammopathy; conditions characterised by excessive antibodies (gammaglobulins, immunoglobulins) in the blood. It is typically used for monoclonal proliferations of gammaglobulins.

Gammopathy

Gammopathy is a condition characerised by excessive antibodies (gammaglobulins, immunoglobulins) in the blood. It is typically used for a monoclonal proliferation of gammaglobulins.

Ganglia

Ganglia: plural of ganglion; in medicine, there are two types of ganglia: cystic masses associated with tendons or joints; collections of nerve cell bodies as in dorsal root ganglia.

Ganglion

Ganglion derives from the Greek meaning a knot or tumour. In dermatology, a ganglion is a cyst typically associated with a tendon sheath or joint capsule of the hand. In neurology, a ganglion is a group of nerve cell bodies such as a dorsal root ganglion from which shingles emerges.

Ganglions

Ganglions: plural of ganglion; in medicine, there are two types of ganglions: cystic masses associated with tendons or joints; collections of nerve cell bodies as in the dorsal roots.

Gangrene

Gangrene is the local decomposition, necrosis, or putrefaction of a body site or tissue.

Gastroenteritis

Gastroenteritis ('gastro' for short) is inflammation of the stomach and intestinal mucosa. Common usage of gastroenteritis implies an infectious cause, but drugs can also cause gastroenteritis.

Gel

Gel is an aqueous solution thickened with polymers such as methylcellulose for topical application especially on hairy skin. A gel tends to dry on the skin surface.

Gelatinous

Gelatinous is an adjective pertaining to gelatin, having a resemblance to jelly.

Gender

Gender is how a person identifies as male, female, or other, and includes social and cultural factors rather than biological differences.

Gene

Gene is the biological unit of heredity. A gene is encoded in DNA or RNA, and is usually located on a chromosome in the genome.

General anaesthetic

General anaesthetic (American spelling anesthetic) is a mixture of drugs to render painfree, unconsciousness, and sometimes also muscle relaxation if required. General anaesthetic can also be used as an adjective pertaining to the induction of general anaethesia, eg, a general anaesthetic drug.

Generalised

Generalised (American spelling generalized) is an adjective meaning widespread or extensive. A generalised rash is distributed over most of the body surface area. (generalized/widespread/disseminated).

Genes

Genes: plural of gene; the biological units of heredity.

Genetic

Genetic is an adjective pertaining to a gene. Examples include genetic code and genetic disease.

Genetic predisposition

Genetic predisposition is the susceptibility to a disease or condition as a result of inheriting risk factors from one or both parents.

Genital

Genital: adjective pertaining to the external sexual organs.

Genitalia

Genitalia: the external male and female reproductive organs.

Genitourinary

Genitourinary is an adjective pertaining to the interconnected genital and urinary organs of the body. Urogenital can also be used.

Genodermatoses

Genodermatoses: plural of genodermatosis; genetically determined skin conditions.

Genodermatosis

Genodermatosis is a genetically determined skin condition.

Genome

Genome is an organism's complete set of genetic material. It includes all the genes and information required to construct that organism. In eukaryotes the genome is stored in the nucleus. Although a genome in a nucleus is constructed of double-stranded DNA, some viral genomes are made from single- or double-stranded RNA.

Genotype

Genotype is the genetic message at a specific gene locus or the whole genome. The genotype can be sequenced looking for mutations or identifying alleles at a locus. Mutations in the genotype may or may not affect the phenotype.

Genotypes

Genotypes: plural of genotype; genetic messages at specific gene loci or whole genomes.

Genotyping

Genotyping is the process of determining and comparing genetic differences between individuals, using biological assays and nucleic acid sequencing.

Germline

Germline is a noun and adjective pertaining to the genetic material passed to offspring, the next generation. The germline is the cells that produce gametes, the cells by which genetic material is passed between generations. In humans, these gametes are the sperm in men and the ova (eggs) in women. Germline as an adjective describes the genetic material passed from a parent, eg, germline mutation meaning every cell in the offspring carries the same mutation.

Germline mutation

Germline mutation is a gene mutation in the gametes (sperm or ova), so will be passed to offspring. All cells in the offspring will carry the mutation.

Germline mutations

Germline mutations: plural of germline mutation; gene mutations in the gametes (sperm or ova), so will be passed to offspring. All cells in the offspring will carry the mutations.

Gestation

Gestation is the period of time taken for a development. In biology it is typically used to mean the time from conception to birth.

Gestational

Gestational is an adjective pertaining to gestation, the period between conception and birth.

Giant cell

Giant cell is a histological term for an unusually large cell, often with a multiple nuclei.

Giant cells

Giant cells: plural of giant cell; unusually large cells seen on histology, often with multiple nuclei.

Gigantism

Gigantism means abnormal or unusual largeness which may be localised (for example of the vulval labia minora), or generalised due to a pituitary adenoma in childhood.

Gingiva

Gingiva is the gums in the mouth.

Gingivae

Gingivae: plural of gingiva, the gums in the mouth.

Gingival

Gingival is an adjective relating to the gingiva, gums.

Glabella

Glabella is the anatomical term for the skin between the eyebrows above the nose.

Glabrous

Glabrous is an adjective meaning smooth. In dermatology it is used to describe a smooth hairless surface, specifically the palms and soles which lack hair follicles and sebaceous glands.

Gland

Gland is an organ that produces and secretes a substance with a specific function either within the body (endocrine gland) or to the exterior (exocrine gland).

Glands

Glands: plural of gland; organs that produce and secrete substances with specific functions in the body.

Glandular

Glandular is an adjective pertaining to a gland(s), organs that produce and secrete substances with specific functions in the body.

Glaucoma

Glaucoma is increased pressure in the eye. It may be classified as open-angle (excessive intraocular fluid production) or closed-angle (an inability to drain the fluid normally). Glaucoma can result in optic nerve damage and blindness.

Globular

Globular is an adjective pertaining to a globule, a small round structure or particle.

Globule

Globule is a small round structure or particle.

Globules

Globules: plural of globule; small round structures or particles.

Glossitis

Glossitis is inflammation of the tongue.

Glucocorticoid

Glucocorticoid, also called a glucocorticosteroid, is a family of steroid hormones produced in the cortex of the adrenal gland, with effects mainly on carbohydrate metabolism, eg, cortisol. Topical, inhaled or systemic treatments may include a synthesised glucocorticoid (cortisone).

Glucocorticoids

Glucocorticoids: plural of glucocorticoid; steroid hormones produced in the cortex of the adrenal gland, with effects mainly on carbohydrate metabolism, eg, cortisol. Glucocorticoids can also be synthesised for topical, inhaled or systemic treatment.

Glucocorticosteroid

Glucocorticosteroid, also called a glucocorticoid, is a (cortico)steroid hormone produced in the cortex of the adrenal gland, with effects mainly on carbohydrate metabolism, eg, cortisol. Topical, inhaled or systemic treatments may include a synthesised glucocorticosteroid (cortisone).

Glucocorticosteroids

Glucocorticosteroids: plural of glucocorticosteroid; steroid hormones produced in the cortex of the adrenal gland, with effects mainly on carbohydrate metabolism, eg, cortisol. Glucocorticosteroids can also be synthesised for topical, inhaled or systemic treatment.

Glucose

Glucose, also called dextrose, is a simple sugar molecule found in plants and animals used as a source of energy by living cells; it is the main sugar found in the bloodstream and it is the glucose level that is meant by 'blood sugar'.

Gluteal

Gluteal is an adjective pertaining to gluteus, the buttocks.

Gluteus

Gluteus is a buttock muscle, of which there are three specfic types.

Glycoprotein

Glycoprotein is a protein with a carbohydrate component.

Glycoproteins

Glycoproteins: plural of glycoprotein; proteins with a carbohydrate component.

Granular

Granular is an adjective pertaining to granules, small intracellular particles seen on microscopy of tissue.

Granular layer

Granular layer of the epidermis (stratum granulosum) is characterised by flattened cells filled with dark granules containing keratohyaline protein.

Granulation tissue

Granulation tissue is a mass of new capillaries, fibroblasts, and inflammatory cells in a healing wound.

Granule

Granule is a tiny quantity of a solid substance. In microscopy it usually refers to a small intracellular particle.

Granules

Granules: plural of granule; small intracellular particles.

Granulocyte

Granulocyte is a type of white blood cell (leukocyte) with a cytoplasm filled with microscopic granules containing enzymes and other proteins important in innate immunity. Neutrophils, basophils and eosinophils are the three most common forms of granulocyte in the blood.

Granulocytes

Granulocytes: plural of granulocyte; white blood cells with cytoplasmic granules.

Granuloma

Granuloma is a histological term for a chronic inflammatory pattern characterised by the localised aggregation of histiocytes with or without other inflammatory cells, with or without necrosis, with or without vasculitis, with or without calcification, with or without foreign bodies. A granuloma may be due to infection, chronic inflammatory disease, or reaction to foreign material.

Granulomas

Granulomas: plural of granuloma; a histological term for a chronic inflammatory pattern characterised by localised aggregations of histiocytes with or without other inflammatory cells, with or without necrosis, with or without vasculitis, with or without calcification, with or without foreign bodies. Granulomas may be due to infection, chronic inflammatory disease, or reactions to foreign material.

Granulomatous

Granulomatous is an adjective pertaining to granulomas, a type of chronic inflammation characterised by histiocytes.

Grenz zone

Grenz zone is a histological term for an apparently uninvolved area (zone) of papillary dermis separating the epidermis from an inflammatory or tumour cell infiltrate in the dermis.

Ground substance

Ground substance is the gel component of the dermis. It contains hyaluronic acid, dermatan sulphate, chondroitin-6-sulphate, anionic polysaccharides, and glycosaminoglycans. It does not include the fibres such as collagen and elastin, or cells.

Grouped

Grouped is an adjective pertaining to a cluster. A cluster of lesions may be described as grouped.

Growth factor

Growth factor is a protein involved in the regulation of cellular growth, proliferation, and differentiation under controlled conditions, eg, epidermal growth factor.

Growth factors

Growth factors: plural of growth factor; proteins involved in the regulation of cellular growth, proliferation, and differentiation under controlled conditions.

Gustatory

Gustatory is an adjective pertaining to taste.

Guttate

Gutatte means drop-like, a pattern resembling tear-drops or rain-drops.

Gynaecomastia

Gynaecomastia (American spelling gynecomastia) is enlarged breast tissue in a male.

Gyrate

Gyrate is an adjective meaning spiral-like or rotating. In dermatology it is used to describe a pattern that is convoluting, winding, or coiled.

Gyrate rash

Gyrate rash is arranged in circles or spirals.

Gyrate rashes

Gyrate rashes: plural of gyrate rash; are arranged in circles or spirals.

Haemagglutination

Haemagglutination (American spelling hemagglutination) is the agglutination (process of clumping) of red blood cells. As this can be seen without needing a microscope it is used in laboratories for blood typing, and to detect antibodies, viruses, or other infectious micro-organisms.

Haemangioma

Haemangioma (American spelling; hemangioma) is a benign proliferative blood vessel tumour, often developmental in origin.

Haemangiomas

Haemangiomas: plural of haemangioma; (American spelling hemangiomas/hemangioma); benign blood vessel tumours often developmental in origin.

Haemarthrosis

Haemarthrosis: bleeding into a joint.

Haematocrit

Haematocrit (American spelling hematocrit) is defined as the ratio of the volume of red blood cells to the total volume of blood. It is measured by separating red blood cells from plasma by centrifugation.

Haematogenous

Haematogenous (American spelling hematogenous) is an adjective pertaining to blood, its production, constituents, dissemination, or derivation, eg, haematogenous spread of a cancer means cancer cells have been spread via the bloodstream.

Haematological

Haematological (American spelling hematological) is an adjective pertaining to haematology, the blood system.

Haematologist

Haematologist (American spelling hematologist) is a medical specialist in the care and study of blood disorders.

Haematology

Haematology (American spelling hematology) is the study of blood disorders.

Haematoma

Haematoma (American spelling hematoma) is a localised swelling due to a collection of blood in or under the skin.

Haematomas

Haematomas: plural of haematoma (American spelling hematomas/hematoma); localised swellings due to collections of blood in or under the skin.

Haemoglobin

Haemoglobin (American spelling hemoglobin) is a family of iron-containing proteins in red blood cells.

Haemoglobins

Haemoglobins: plural of haemoglobin (American spelling hemoglobins/hemoglobin); iron-containing proteins in red blood cells.

Haemolysis

Haemolysis (American spelling hemolysis) is the rupture or destruction of red blood cells.

Haemolytic

Haemolytic (American spelling hemolytic) is an adjective pertaining to the rupture or destruction of red blood cells.

Haemophagocytic syndrome

Haemophagocytic syndrome: is defined by the triad of fever, enlarged spleen, and cytopenias.

Haemophagocytosis

Haemophagocytosis (hemophagocytosis): the swallowing (phagocytosis) of intact red and white blood cells, and platelets (haemopoeitic cells) by histiocytes in the bone marrow or other tissues.

Haemophilia

Haemophilia (American spelling hemophilia) is a group of genetic conditions characterised by delayed clotting of blood due to an absent or defective clotting factor.

Haemorrhage

Haemorrhage (American spelling hemorrhage) is a noun and verb pertaining to a bleed or to bleed.

Haemorrhages

Haemorrhages: plural of haemorrhage (American spelling hemorrhages); as a noun means loss of blood from a blood vessel; as a verb means to be losing blood.

Haemorrhagic

Haemorrhagic (American spelling hemorrhagic) is an adjective pertaining to haemorrhage, a bleed, eg, a haemorrhagic bulla is a blood-filled blister.

Haemosiderin

Haemosiderin (American spelling hemosiderin) is the brown iron-containing pigment derived from blood.

Haemosiderosis

Haemosiderosis (American spelling hemosiderosis) is the accumulation of haemosiderin, a form of iron, in tissues usually as a result of bleeding.

Haemostasis

Haemostasis (American spelling hemostasis) is the process that stops blood flow in bleeding or haemorrhage. This can be achieved surgically during a procedure using sutures or diathermy.

Hair

Hair is a specialised epidermal product of the pilosebaceous structure, made of keratin. Terminal hair is found on the scalp; vellus hair on body surface; lanugo hair on the fetus.

Hair cycle

Hair cycle consists of a growth phase (anagen); a short involutional phase (catagen); a resting phase (telogen).

Hair pull test

Hair pull test is used for assessing a patient complaining of hair loss. If more than 10% of hairs in a pulled bundle are removed, the result is considered abnormal (positive). None, one or two hairs removed when gently tugging on a bundle of 50-60 hairs is considered normal.

Hair-pull test

Hair-pull test is used for assessing a patient complaining of hair loss. If more than 10% of hairs in a pulled bundle are removed, the result is considered abnormal (positive).

Hamartoma

Hamartoma is a benign overgrowth of a mature cell type normal to the site or organ. In the skin a hamartoma often presents as a birthmark (congenital naevus), but may first develop, appear, or be noticed in adult life (acquired). Examples include naevus sebaceous, follicular hamartoma, and chondroid syringoma.

Hamartomas

Hamartomas: plural of hamartoma; benign overgrowths of a mature cell type normal to the site or organ. They may be congenital or acquired.

Haploid

Haploid is an adjective describing a cell with only one set of chromosomes, as is typically seen in gametes (ova and sperm).

Heliotrope

Heliotrope is a purple flowering plant, and is used to describe a pink-purple colour reminiscent of the flower.

Helminth

Helminth is a parasitic worm. Examples of a helminth include a tapeworm, liver fluke, roundworm, and leech.

Helminths

Helminths; plural of helminth; parasitic worms including tapeworms, liver flukes, roundworms, and leeches.

Hemidesmosome

Hemidesmosome is a structure in the basemement-membrane zone, made by the epidermal basal keratinocytes, and involved in sticking the basal keratinocytes to the dermis.

Hemidesmosomes

Hemidesmosomes: plural of hemidesmosome; structures in the basemement-membrane zone, made by the epidermal basal keratinocytes and involved in sticking the basal keratinocytes to the dermis.

Hemifacial

Hemifacial is an adjective pertaining to half the face.

Hepatic

Hepatic is an adjective relating to the liver.

Hepatitis

Hepatitis is inflammation of the liver.

Hepatocyte

Hepatocyte is the main functioning cell in the liver.

Hepatocytes

Hepatocytes: plural of hepatocyte; the main functioning cells in the liver.

Hepatomegaly

Hepatomegaly is enlargement of the liver.

Hepatosplenomegaly

Hepatosplenomegaly is abnormal enlargement of both the liver and spleen.

Hepatotoxic

Hepatotoxic is an adjective pertaining to liver-damaging properties or effects.

Hepatotoxicity

Hepatotoxicity is a toxic hepatitis, a state of liver damage due to liver-damaging chemicals. Hepatotoxicity is also a measure of the degree a chemical will cause liver damage, eg, the hepatoxicity of a drug.

Hepatotoxin

Hepatotoxin is a chemical that damages the liver.

Hepatotoxins

Hepatotoxins: plural of hepatoxin; chemicals that damage the liver.

Hereditary

Hereditary is an adjective pertaining to inheritance. In medicine, it is used to describe a genetic (inherited) mutation or condition.

Herpetiform

Herpetiform is an adjective meaning to resemble herpes, so is used to describe clustered vesicles and does not imply a viral origin.

Herpetiformis

Herpetiformis, see also herpetiform, describes grouped or clustered vesicles or papules, resembling herpes

Heterogeneous

Heterogeneous is an adjective pertaining to having diverse or various causes or content.

Heterogenous

Heterogenous refers to a structure having a foreign origin.

Heterozygosity

Heterozygosity is the noun meaning the two copies of a specific gene are different alleles, ie, heterozygosity at a gene locus.

Heterozygous

Heterozygous is an adjective pertaining to heterozygosity, the two copies of a gene are different alleles, eg, in an autosomal dominant condition the relevant gene is heterozygous.

Hilar lymphadenopathy

Hilar lymphadenopathy is enlarged mediastinal lymph nodes usually detected on chest X-ray.

Histamine

Histamine, 2-[4-imadazolyl]ethylamine, is stored in the granules of mast cells and basophils, and released rapidly via an IgE-mediated mechanism during hypersensitivity and inflammation. Local histamine release causes capillary vasodilation and plasma leakage. In anaphylaxis large amounts of histamine are released with systemic effects on smooth muscle and blood pressure.

Histiocyte

Histiocyte is a tissue macrophage; a phagocytic cell important in granuloma formation.

Histiocytes

Histiocytes: plural of histiocyte; tissue macrophages. Histiocytes are important in the formation of granulomas and can fuse to form multinucleated giant cells.

Histiocytic

Histiocytic is an adjective pertaining to histiocytes, phagocytic tissue cells.

Histiocytosis

Histiocytosis is a group of diseases characterised by too many histiocytes in the skin and other organs. There are two main types of histiocytosis: Langerhans cell histiocytosis and non-Langerhans histiocytosis, which are further subdivided.

Histological

Histological is an adjective pertaining to histology, the study of the microscopic appearance of normal and abnormal biological tissues.

Histologically

Histologically is an adverb pertaining to histology, the study of the microscopic appearance of biological tissue.

Histology

Histology is the study of the microscopic appearance of normal and abnormal biological tissues.

Histopathological

Histopathological is an adjective pertaining to histopathology, the science of the microscopic assessment of diseased, abnormal tissue.

Histopathologically

Histopathologically is an adverb pertaining to histopathology, the science of the microscopic assessment of diseased and abnormal tissue.

Histopathology

Histopathology is the study of the microscopic appearance of biological tissues to help in the diagnosis of disease.

HIV

HIV is an acronym for human immunodeficiency virus.

HLA

HLA is an acronym for human leukocyte antigen(s), a complex of proteins expressed on human cells that help the immune system to distinguish self. HLA is the human version of the Major Histocompatibility Complex (MHC). HLA typing is also known as tissue typing, and is important for matching organ donors and recipients. Specific HLA types can be associated with disease susceptibility risk.

Homeostasis

Homeostasis is the state of equilibrium in the body created by its self-regulating processes. Illness, injury and chronic medical conditions can disrupt homeostasis.

Homogeneous

Homogeneous is an adjective to describe being uniform throughout, all the same.

Homogenous

Homogenous describes a thing or things as being the same throughout.

Homozygosity

Homozygosity is a noun meaning the two copies of a specific gene are the same allele, ie homozygosity at a gene locus.

Homozygous

Homozygous is an adjective pertaining to homozygosity, identical alleles of a specific gene, eg, an autosomal recessive condition requires the relevant gene to be homozygous.

Horn

Horn is a hard structure composed predominantly of bone which may have an epidermal coating. However a cutaneous horn in human skin is an accumulation of hard keratin attached to the skin surface.

Horner Syndrome

Horner syndrome is a sympathetic nerve disorder defined by a classic triad of symptoms usually involving only one side of the face: a small unresponsive pupil; droopy upper eyelid; loss of facial sweating.

Horny layer

Horny layer of the epidermis (stratum corneum) consists of stacks of keratinised dead cells without nuclei. The top layer of these cells loosens and falls off.

Host

Host, in biology, is the cell, animal, or plant on which a parasitic organism lives. Host can also be used to mean self as in a host or self antigen being recognised as foreign.

Hosts

Hosts: plural of host; in biology the cells, animals, or plants on which parasitic organisms live.

Human leukocyte antigen

Human leukocyte antigen (acronym HLA) is a complex of proteins expressed on human cells that help the immune system to distinguish self from foreign.

Humectant

Humectant is a substance that attracts moisture. Naturally occurring humectants are found in the dermis. A humectant may be used as a skin moisturiser and examples include glycerine, sorbitol, urea, hyaluronic acid and alpha-hydroxy acids.

Humectants

Humectants: plural of humectant; substances that attract moisture. Naturally occurring humectants can be found in the dermis. Humectants may be used as skin moisturisers and examples include glycerine, sorbitol, urea, hyaluronic acid and alpha-hydroxy acids.

Humid

Humid is an adjective pertaining to humidity, the water content of air; humid air has a high moisture content.

Humidity

Humidity is a measure of the moisture content of air.

Hyaline

Hyaline is eosinophilic amorphous material resulting from degeneration of collagen in the superficial dermis, a word used in dermatopathology.

Hyalinisation

Hyalinisation is the process of forming hyaline in the dermis resulting in a ground-glass appearance, a word used in dermatopathology.

Hyalinised

Hyalinised is an adjective pertaining to hyaline; a ground-glass appearance due to collagen degeneration.

Hydrocephalus

Hydrocephalus is an excess of cerebrospinal fluid in the brain.

Hydrophilic

Hydrophilic is an adjective pertaining to the ability to combine with or dissolve in water.

Hydrophobic

Hydrophobic is an adjective pertaining to the inability or failure to mix with water.

Hydrostatic pressure

Hydrostatic pressure: is the pressure exerted by a fluid, a water pushing force.

Hyperaesthesia

Hyperaesthesia (American spelling hyperesthesia) is an abnormal increase in skin sensitivity to light touch, usually with a neurological cause.

Hyperalgesia

Hyperalgesia is an abnormal increase in sensitivity to a painful stimulus, usually with a neurological cause.

Hyperbaric

Hyperbaric is an adjective pertaining to increased gas pressure.

Hypercalcaemia

Hypercalcaemia (American spelling hypercalcemia) means the calcium level in the blood is higher than normal.

Hypercalciuria

Hypercalciuria means the calcium level in the urine is higher than normal.

Hypercholesterolaemia

Hypercholesterolaemia (American spelling hypercholesterolemia) is a higher than healthy blood level of cholesterol, a high cholesterol blood level.

Hyperchromatic

Hyperchromatic is an adjective pertaining to increased chromatin, the condensed DNA and protein in the cell nucleus. It is used in histology to describe darker than usual staining of the cell nucleus, eg, hyperchromatic nuclei in skin malignancies.

Hyperchromatism

Hyperchromatism is increased nuclear staining due to clumping of the nuclear chromatin, a word used in histopathology.

Hypercoagulability

Hypercoagulability is the tendency for blood to clot more easily than normal.

Hypercoagulable

Hypercoagulable is an adjective pertaining hypercoagulability, tendency toward increased clotting of blood.

Hyperglycaemia

Hyperglycaemia (American spelling hyperglycemia) is high blood glucose (sugar) level.

Hypergranulosis

Hypergranulosis is an increased numbers of intracellular granules within the granular layer of the epidermis compared to normal, a word used in dermatopathology.

Hyperhidrosis

Hyperhidrosis is excessive sweating and be localised to one body site, eg, palms, or  generalised, affecting the whole body.

Hyperkalaemia

Hyperkalaemia (American spelling hyperkalemia) is a higher than normal potassium level in the blood.

Hyperkeratosis

Hyperkeratosis is a thickening of the stratum corneum, the outermost layer of the skin.

Hyperkeratotic

Hyperkeratotic is an adjective pertaining to hyperkeratosis, thickening of the stratum corneum, the outermost layer of the skin.

Hyperlipidaemia

Hyperlipidaemia (American spelling hyperlipidemia) is a higher than normal blood level of one or more of the lipids (fats) such as cholesterol or triglycerides.

Hyperpigmentation

Hyperpigmentation is a darker colour than normal for that person or site, due to increased pigment. It can be localised or generalised.

Hyperpigmented

Hyperpigmented is an adjective pertaining to hyperpigmentation, increased colour due to pigment. Hyperpigmented skin is darker than normal for that site, individual or population.

Hyperplasia

Hyperplasia is the enlargement of a tissue by an increase in cell numbers.

Hyperplastic

Hyperplastic is an adjective pertaining to hyperplasia; enlargement due to increased cell numbers.

Hyperproliferation

Hyperproliferation is increased proliferation (replication) of cells.

Hyperproliferative

Hyperproliferative is an adjective pertaining to hyperproliferation, increased replication of cells.

Hyperproteinaemia

Hyperproteinaemia: abnormally high protein level in the blood.

Hypersensitivity

Hypersensitivity is an exaggerated immune reaction to an allergen or antigen following sensitisation. There are several types of hypersensitivity reaction: type I (immediate); type II (cytotoxic); type III (immune complex); type IV (delayed, T-cell mediated). Non-allergic hypersensitivity is a pseudoallergy as it does not involve the immune system.

Hypertension

Hypertension is high blood pressure.

Hypertensive

Hypertensive is an adjective pertaining to hypertension, high blood pressure.

Hyperthyroid

Hyperthyroid is an adjective pertaining to hyperthyroidism, overproduction of thyroid hormone.

Hyperthyroidism

Hyperthyroidism is the overproduction of thyroid hormone by the thyroid gland.

Hypertonic

Hypertonic is an adjective with several meanings. Hypertonic pertains to having a comparatively high osmotic pressure (eg, a hypertonic solution); and pertains to hypertonia, increased muscle tone (eg, hypertonic bladder).

Hypertrichosis

Hypertrichosis is excessive hair growth, not in the patterned distribution of hirsutism. Hypertrichosis may be localised or generalised.

Hypertriglyceridaemia

Hypertriglyceridaemia (American spelling hypertriglyceridemia) is a higher than healthy level of triglyceride in the blood.

Hypertrophic

Hypertrophic is an adjective pertaining to hypertrophy, excessive growth, overgrowth.

Hypertrophied

Hypertrophied is an adjective pertaining to hypertrophy, thickening or enlargement of a part due to enlargement of the cells and not due to an increased number of cells.

Hypertrophy

Hypertrophy is excessive growth or enlargement.

Hyperviscosity

Hyperviscosity is an adjective pertaining to increased viscosity. In medicine it describes thick, sticky blood with poor flow due to increased or abnormal cells or proteins.

Hyphae

Hyphae, plural of hypha, long filaments of fungi that form the mycelium.

Hyphema

Hyphema: blood between the cornea and iris, the anterior chamber of the eye.

Hypogeusia

Hypogeusia means decreased sense of taste.

Hypoglycaemia

Hypoglycaemia (American spelling hypoglycemia) is a low blood glucose (sugar) level.

Hypoglycaemic

Hypoglycaemic is an adjective pertaining to hypoglycaemia, low blood glucose (sugar).

Hypogonadism

Hypogonadism is underactivity or inadequate function of the gonads (reproductive glands) leading to impaired production of germ cells and sex hormones.

Hypohidrosis

Hypohidrosis is decreased sweating.

Hypohidrotic

Hypohidrotic is an adjective pertaining to hypohidrosis, reduced sweating.

Hypomelanosis

Hypomelanosis means reduced or absent melanin in the epidermis of the skin.

Hypomelanotic

Hypomelanotic is an adjective pertaining to hypomelanosis, localised melanin pigment reduction or loss.

Hypomorphic

Hypomorphic is an adjective pertaining to a gene mutation that results in reduced (but not lost) function.

Hyponychium

Hyponychium is the skin under the distal free end of the nail plate.

Hypophysitis

Hypophysitis is inflammation of the pituitary gland or stalk.

Hypopigmentation

Hypopigmentation is colour that is paler than normal for that person or site, due to reduced pigment. It may be generalised or localised.

Hypopigmented

Hypopigmented is an adjective pertaining to hypopigmmentation, paler colour due to reduced pigment. Hypopigmented skin is lighter in colour compared to normal for that site, individual, or population.

Hypoproteinaemia

Hypoproteinaemia: low protein level in the blood.

Hypotension

Hypotension is low blood pressure.

Hypotensive

Hypotensive is an adjective pertaining to hypotension, low blood pressure.

Hypothalamic

Hypothalamic is an adjective pertaining to the hypothalamus; that part of the brain which coordinates the autonomic nervous system and controls pituitary gland activity.

Hypothalamus

Hypothalamus is the part of the brain that coordinates the autonomic nervous system and controls pituitary gland activity.

Hypothermia

Hypothermia is a low body temperature. It happens when the body is losing more heat than it can make. In dermatology, hypothermia may complicate conditions associated with extensive skin redness as in erythroderma. Hypothermia can be a medical emergency.

Hypothermic

Hypothermic is an adjective pertaining to hypothermia, a low body temperature.

Hypothyroid

Hypothyroid is an adjective pertaining to hypothyroidism, underproduction or insufficient thyroid hormone.

Hypothyroidism

Hypothyroidism is insufficient circulating thyroid hormone resulting from underproduction by the thyroid gland.

Hypotonia

Hypotonia is decreased muscle tone, a state in which the muscle is always relaxed.

Hypotonic

Hypotonic is an adjective with several meanings. Hypotonic pertains to having a comparatively low osmotic pressure (eg, a hypotonic solution); pertaining to hypotonia, decreased muscle tone.

Hypotrichosis