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This resource focuses on side effects and other terms used in medicines information and assessments of medicines. It does not include terms that are used only rarely, nor does it cover most disease states or technical terms.
How to use EMA’s medical terms simplifier
- You can search for a term or click on a letter below to see terms beginning with that letter.
- Each entry contains a short description. For some, a longer or alternative description is available by selecting the term.
- We use ‘< >’ to indicate alternative or optional wording.
EMA’s medical terms simplifier will be updated periodically. For comments or suggestions, you can use our Medical terms simplifier comments form.
C
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C-reactive protein
a marker of inflammation -
Cachexia
muscle wasting with significant weight loss -
Calcitonin
a hormone <produced by the thyroid gland> that helps to control the amount of calcium and phosphorus in the blood -
Candidiasis
thrush, a fungal infection <caused by Candida> -
Cannula
a thin tube inserted into <the body><a vein> -
Cannula, indwelling intravenous
a thin tube permanently inserted into a vein -
Capillary leak syndrome
leakage of fluid from blood vessels causing tissue swelling and a drop in blood pressure -
Capsid
shell (of a virus) -
Carcinoid syndrome
symptoms caused by <cancerous> tumours that release substances into the blood <that act on different organs> -
Carcinoid tumour
a tumour of the endocrine system that produces hormones -
Carcinoma
a type of cancer -
Cardiac
heart -
Cardiac arrest
heart stops beating -
Cardiac arrhythmia
see arrhythmia -
Cardiomyopathy
damage to the heart muscle -
Cardiotoxicity
harm to the heart -
Cardiovascular
affecting the heart and blood circulation -
Cardiovascular system
heart and blood vessels -
Cardioversion
a process that restores the heart's normal rhythm -
Cartilage
tough, flexible tissue in joints and other areas such as the nose and ears -
Castration
surgical or chemical prevention of the effects of male hormones <released by the testes> -
Catalyse
help -
Cataplexy
sudden muscle weakness and collapse caused by a strong emotion or laughter <in people with narcolepsy> -
Cataract
clouding of the lens -
Catheter
a flexible tube inserted into the body -
CD4 T-cells
white blood cells that are important in helping to fight infections -
Cellulitis
inflammation of the deep skin tissue -
Central nervous system
brain and spinal cord -
Central venous catheter
see central venous line -
Central venous line
a tube through the skin into a large vein <used for giving medicines and fluids> -
Cerebral
of <cerebrum, a part of> the brain -
Cerebral oedema
see oedema, cerebral -
Cerebrospinal fluid
fluid that surrounds the brain and the spinal cord -
Cerebrovascular accident
stroke -
Cerebrovascular disease
disease of the blood vessels supplying the brain -
Cervical cancer
cancer of the cervix -
Cervical dystonia
twisting and pulling of the neck and head caused by abnormal tightening of neck muscles -
Cervix
the neck of the womb -
CHD
see coronary heart disease -
Chelate
[explain in text] 'attaches to another chemical to form a 'chelate' that can be removed from the body in the stools' -
Cholestasis
reduced flow of bile from the liver <because of a blockage> -
Cholestatic hepatitis
see hepatitis, cholestatic -
Choroid
the layer below the retina that contains blood vessels -
Chromatopsia
changes in colour perception -
Chromosomal translocation
when parts of genes are rearranged between two chromosomes -
Chromosome
genetic material -
Chronic
long term -
Chronic renal failure
see renal failure, chronic -
Chronic stable angina pectoris
see angina pectoris -
Circumoral
around the mouth -
Cirrhosis
<scarring of the liver> <a type of liver disease> -
Cirrhosis, biliary
liver damage caused by build-up of bile -
Coagulation
clotting -
Coagulopathy
problems with blood clotting -
Cognitive
ability to think, learn and remember -
Colitis
inflammation in the large bowel <causing pain and diarrhoea> -
Colloidal
solid particles evenly spread in a liquid -
Colon
lower part of the gut -
Colonoscopy
a procedure to examine the large bowel though a tube with a camera -
Colorectal cancer
a cancer that starts in the large bowel and involves the rectum (the lowest part of the gut) -
Community-acquired infection
infection that has been caught outside of hospital -
Compensated liver disease
see liver disease, compensated -
Complete response
no sign of cancer after treatment -
Compliance
the ability of patients to stick to their treatment -
Complicated flu
see flu, complicated -
Complicated infection
see infection, complicated -
Congenital
present at birth -
Congestive heart failure
see heart failure, congestive -
Conjunctiva
the membrane that lines the white of the eye and the inside of the eyelid -
Conjunctivitis
redness and discomfort in the eye -
Connective tissue
the tissue that binds and supports the skin and internal organs -
Constriction
narrowing -
Contraception
prevention of pregnancy -
Contrast agent
a compound that helps make internal body structures easier to see during imaging and medical procedures -
Contusion
bruising -
Convulsion
an episode of spasm(s) and reduced consciousness -
Cornea
the transparent layer in front of the eye that covers the pupil and iris -
Corneal opacity
clouding of the cornea -
Coronary arteries
blood vessels that supply the heart muscle -
Coronary artery disease
see coronary heart disease -
Coronary heart disease
heart disease caused by narrowing or blockage of blood vessels supplying the heart muscle -
Corpora cavernosa
the spongy tissue of the penis -
Corpscular volume
size of the red blood cells -
Creatine kinase
an enzyme released into the blood when muscle is damaged -
Creatine phosphokinase (CPK)
see creatine kinase -
Creatinine
a breakdown product of muscle <removed by the kidneys> -
Creatinine (elevated)
a sign of <worsening> kidney problems -
Creatinine clearance
a measure of how well the kidneys are working -
Crepitation
unusual crackling sound -
Crohn’s disease
an inflammatory disease affecting the gut -
Cryotherapy
freezing -
Crystalluria
<crystal> particles in the urine -
Cushing’s syndrome
disorder with signs such as weight gain, fat build-up on the face and bruising caused by too much of <a type of steroid> <corticosteroid> hormone -
Cutaneous small vessel vasculitis
inflammation of blood vessels in the skin <which may result in a rash or bruising> -
Cyanosis
skin and lips turning blue <because of a lack of oxygen> -
Cystitis
<inflammation> <infection> in the bladder <which can cause pain and discomfort when passing urine> -
Cytokine release syndrome
<life-threatening> condition causing fever, vomiting, shortness of breath, headache and low blood pressure -
Cytomegalovirus (CMV) retinitis
a viral infection of the retina, which can cause loss of vision -
Cytopenia
low number of cells in the blood <or tissue> -
Cytotoxic
cell-killing or able to kill <dividing> cells <such as cancer cells>