Medical Terms (A to Z)



Alcohol Dependence

Continued dependence on alcohol, despite the damaging effects - can contribute to permanent liver disease, pancreatitis and alcoholic dementia amongst other serious health conditions.

Alzheimer’s Disease

An incurable, degenerative and terminal illness, the most common form of dementia. Affects memory (loss of existing memories and difficulty forming new ones) and personality, and gradually leads to loss of bodily function.


Deficiency in red blood cells, can lead to a lack of oxygen supplied to organs, also causing weakness or fatigue, poor concentration and potentially heart complications.


A balloon in an artery wall, caused by weakness or disease. High blood pressure can also be a contributing factor. These are often found in the aorta, brain and coronary arteries. If the aneurysm ruptures it can be fatal. 

Angina Pectoris

Chest pains due to lack of blood and oxygen supply to the heart muscle.

Ankylosing Spondylitis

Chronic condition where various areas of the spine and joints become inflamed.

Aortic Stenosis

Narrowing of the aortic valve with consequential restriction of blood flow, which can be evident by the presence of a heart murmur.


Irregularity of the heart beat caused by an interruption of the normal electrical activity in the heart, often controlled by medication to regulate or slow the beat, although in some cases a cardioversion procedure (in which an effort is made to 'shock' the heart back into correct rhythm) or implantation of a pacemaker are necessary. Can vary from very mild palpitations, to serious, life threatening irregularity which if left uncorrected could contribute to clot formation or cardiac arrest. Common types of arrhythmia are Atrial Fibrillation and Supraventricular Tachycardia.

Arterial Occlusion

Blockage of an artery, usually by blood clot or fatty substances. If in the heart it can cause heart attack or typical chest pain (angina).


Progressive hardening of arteries due to disease.


An accumulation of excess fluid in the abdominal cavity, often associated with cirrhosis of the liver.


Persistent respiratory condition with tightness of the chest and difficulty breathing caused by narrowing and spasm of the airways. Pulmonary function tests (FEV or PEFR) are normally done to distinguish between asthma and other more serious types of lung disease.


Uncoordinated movement of muscles, due to dysfunction in the central nervous system (brain and spinal cord).

Atrial Fibrillation
Barrett's syndrome/ Barrett’s Oesophagus

Reflux of stomach acid affecting the lining of the gullet causing abnormal cells, which increases the risk of cancerous cells developing. 

Basal Cell Carcinoma (rodent ulcer)

Slow growing cancerous skin tumour on areas of the body that are subject to excessive sun exposure. 


A small tissue sample that is prepared for examination with a microscope by a pathologist to determine the presence of cell abnormalities and investigation for grading of cancers. 

Bipolar disorder

A mental health condition that causes extreme mood swings that include emotional highs (mania or hypomania) and lows (depression).

Blood Coagulation Disorder

Spontaneous bleeding or family tendency to bleeding or clotting could indicate a tendency to abnormal clotting factors, coagulation defects or blood platelet disorders. Polycythaemia Vera is an example of a medical condition that would be a specific clotting disorder.

Brain Haemorrhage

Bleeding in the brain caused by injury or disease, which causes death of brain tissue, and is a common cause of stroke.


Lung disease which causes widening of the airways, and excess mucus production, development of cysts and inflammation. Treatment can include postural drainage, to remove excess mucus from the lungs.


A class of diseases in which cells display uncontrolled and abnormal growth, destroying surrounding tissues in the body, often leading to formation of a malignant tumour. Cancer can affect any cells including blood cells, and can potentially spread throughout the body (a process called metastasis). It may require surgery, or treatment with chemotherapy or radiotherapy.

Cardiac Catheterisation

A thin flexible hollow tube is inserted into the heart via the blood vessels in the groin or an arm. The most common procedures are Coronary Angiography, Cardiac Ablation, Coronary Angioplasty or Valvuloplasty. 


Heart muscle disease due to deterioration of the muscle, there are several different types, which can cause arrhythmia or heart failure, among various other complications causing the heart not to function properly.

Carotid stenosis

Narrowing of the carotid artery in the neck due to disease, interfering with the normal blood flow which can cause a stroke or blackouts by cutting off the blood -oxygen supply to the brain.

Cerebral Aneurysm

A weakness or thinning of a blood vessel in the brain, causing a ballooning or bulging effect which can rupture (called a haemorrhage).


Treatment of disease, especially cancer, with chemicals which kill cells, particularly the fast-growing ones such as those involved in cancer.


Raised cholesterol in the blood can cause fatty deposits forming a furry layer inside the arteries. Where this occurs in the arteries around the heart and in the neck providing the blood supply to the brain, blood clots, blockages and serious complications can occur. Changing diet and taking medication (such as statins) can lower this level, reducing the risk.

Chronic Bronchitis

Chronic inflammatory condition in the lungs which causes respiratory passages to be swollen and inflamed, and more mucus to be produced. 

Chronic Kidney Disease

Progressive loss of kidney function over a period of months or years. Ranges from stages 1 to 5, from mildly diminished function which rarely necessitates treatment, to severe disease, end-stage kidney disease or kidney failure, which would require dialysis or kidney transplant.

Chronic Obstructive Pulmonary Disease (COPD)

Term used to describe chronic bronchitis, emphysema or both types of irreversible lung disease combined.


A serious liver condition which progresses slowly and often related to heavy alcohol consumption over a number of years, or infection with hepatitis virus. When cirrhosis causes complete liver failure a liver transplant is required.


An ache or cramping pain which occurs during exertion and stops once halting the activity.

The pain is due to too little blood flow in the legs or arms. It can be a sign of Peripheral Vascular Disease.

Continuous Positivity Airway Pressure (CPAP)

Continuous positive airway pressure. Used to treat sleep apnoea, a condition where during sleep the air supply is cut off while inhaling.

Cor Pulmonale

Also known as pulmonary heart disease, resulting in high blood pressure in the blood vessels that travel from the heart to the lungs, this results in pulmonary hypertension and an enlargement of the right side of the heart.

Coronary Artery Disease

Disease of the arteries supplying blood to the heart through the formation of fatty deposits, narrowing or blocking them and reducing the oxygen supply reaching the heart, and potentially leading to a heart attack. Treatment would include medication, and even angioplasty and heart bypass surgery.

Coronary Embolism

An obstruction in the blood vessels that supply the heart can cause a clotting known as an embolism.

Creatinine Clearance

A kidney function test to determine the ability of the kidneys to remove impurities from the blood.

Crohn's Disease

Inflammatory disease of the digestive system, causing pain, diarrhoea, vomiting and weight loss, also anaemia and malabsorption due to these. In severe cases, surgical removal of part or all of the bowel may be necessary.


A common mental health disorder that might be short or long term and may, or may not, require medication or therapy.


A disorder which causes erratic blood sugar levels, which can be due to deficiency in insulin production by the pancreas or body tissue resistance to insulin. It can be controlled by diet, tablets or insulin, depending on severity and type. Long term complications can include eye damage, kidney disease and circulatory and cardiovascular problems, as well as retinopathy, neuropathy and peripheral vascular disease. The more complications there are, the more a person's life expectancy will be diminished. An important test for monitoring diabetes is the HbA1c test. Where the HbA1c shows a poor result there is a very high risk of developing additional complications.


A process of filtration to remove waste products from the blood stream. The blood flows through a machine, a process needed for a patient with severe kidney failure.

Dissecting Aneurysm

The splitting of an arterial wall caused by blood entering a tear in the lining of the blood vessel wall.


Breathlessness or shortness of breath which could be due to a form of heart disease, asthma or chronic lung disease.


A test used by a specialist to assess the structure and function of the heart. Heart valves, heart chambers and heart wall thickness can be measured and assessed for any signs of disease.

Electrocardiogram (ECG)

A test that measures the electrical impulses of the heart to assess heart rhythm disorders or investigate heart strain or heart distress called ischaemia.


A progressive lung condition, causing damage to the structure of the lungs, resulting in irreversible lung disease, treated with inhalers to aid breathing and oxygen in severe cases.


Inflammation of the inner lining of the heart.


A procedure to view the internal organs used for diagnosing or treating certain conditions.


Chronic brain disorder causing recurrent seizures, can be controlled by medication, but can affect ability to carry out occupation.

Fatty Liver

When an abnormal amount of fat accumulates in the liver and within the liver cells often associated with obesity or diabetes, it can instigate an inflammatory process.

Forced Expiratory Volume (FEV)

Forced Expiratory Volume: a test to establish the grading of lung disease.


A scoring system used by medical experts to assess the severity and treatment options in connection with prostate cancer.

Glomerular Filtration Rate (GFR)

Glomerular Filtration Rate – a method of evaluating the function of kidneys.


An inherited blood disorder causing excess of iron in the body which may lead to organ failure, often treated with regular venesection (blood-letting).


A blood disorder where blood clotting is deficient. This is due to insufficient clotting factor, a component of the blood causing the patient to bleed longer than normal.


A blood test to monitor diabetes control which gives a valuable insight into the adequacy of treatment being taken.

Heart Attack

An event caused by lack of blood supply and therefore the oxygen supply to the heart, causing damage to the heart tissue. This is often caused by a blockage from a blood clot or build-up of a fatty substance from cholesterol in the blood. The tissue damage may mean that the heart's pumping function is impaired, causing heart failure as a result.

Heart Bypass (CABG)

A surgical procedure used to treat coronary heart disease. It diverts blood around narrowed or clogged parts of the major arteries to improve blood flow and oxygen supply to the heart.

Heart Failure

An ongoing condition in which a problem with the function or structure of the heart reduces its ability to pump enough blood to the rest of the body. This could be due to damage to the heart muscle caused by heart attack or another cause such as persistent hypertension.

Heart Murmur

As blood flows through the heart there are normal heart sounds generated by the opening and closing of heart valves. A heart murmur is the name given to any abnormal extra heart sounds that may occur. Some heart murmurs are innocent meaning they are not likely to affect a person's longevity. In contrast, a pathological heart murmur is an abnormal and potentially harmful heart murmur that has an impact on a person's longevity.

Heart Transplant

A surgical transplant procedure performed to help a patient with severe heart failure or coronary artery disease, in which the heart is usually replaced with another human heart.

Heart Valve Disease

Disease involving one or more of the heart valves (aortic, mitral, pulmonary or tricuspid), causing leaking, narrowing or insufficiency, can also cause murmurs or arrhythmias. Treated usually with medication, although sometimes surgical repair or replacement of the valve is necessary.

Heart Valve Replacement

Replacement of one or more heart valves with either an artificial mechanical heart valve, or one from a human donor or an animal's tissue.


Enlargement of the liver, due to many causes.


A report created by a pathologist to study cells from a tissue specimen. The tissue is graded and depending on the results the sample could show cancerous changes or it could be benign.


Human immunodeficiency virus which can lead to AIDS, affects immune system so that other infections and diseases can be fatal.

Hodgkin's Lymphoma

A type of cancer that affects the lymphatic system, which is part of the body's germ-fighting immune system.

Hypertension (high blood pressure)

A condition in which the blood pressure is persistently raised, increasing the risk for stroke, heart attacks, heart failure, kidney disease and other conditions.

Hypertrophic Cardiomyopathy

A type of genetic heart muscle disorder in which the muscle is thickened, and has lost its compliance (elastic quality), meaning that blood flow is impaired or insufficient and the heart doesn't function properly.


Implantable cardioverter-defibrillator, a device that electronically controls a patient's heart beat to correct a heart rhythm disorder.

Kidney Failure Progressive

Kidney Function Disorder

An impairment of the kidneys, or decrease in kidney function.

Kidney Transplant

Replacement of a kidney by a donor, usually due to failure of the kidney. This can necessitate ongoing treatment with immunosuppressant drugs to reduce the risk of rejection by the body's defences.


Cancer of the white blood cells, which begin in the bone marrow. Leukaemias are grouped in two ways: the type of white blood cell affected - lymphoid or myeloid; and how quickly the disease develops and gets worse.


A condition, external factor or controllable factor that increases the risk or likelihood of the risk when in combination with other risk factors. Examples are BMI, smoking, alcohol consumption etc.

Liver Disease

Progressive liver damage can result in liver failure which could lead to a need for transplantation. Also see Fatty Liver & Liver Transplant.

Lung Fibrosis

A disease where there is scarring of the lungs (called fibrosis) which makes it difficult to breathe. This is because the scarring causes the tissues in the lungs to get thick and stiff and makes it hard to absorb oxygen into the bloodstream.


Lymphoma is a broad term for cancer that begins in cells of the lymph system. The two main types are Hodgkin lymphoma and non-Hodgkin lymphoma (NHL).

Malignant Melanoma

A type of cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin.

Metabolic Syndrome

A group of conditions that occur together such as cardiovascular disease, diabetes, high cholesterol and high blood pressure which can exist in combination and are a factor in a person's longevity.

Mitral Valve Disease

Mitral valve disease occurs when the mitral valve doesn’t work properly, allowing blood to flow backward into the left atrium. As a result, your heart does not pump enough blood out of the left ventricular chamber to supply your body with oxygen-filled blood. If left untreated, mitral valve disease can lead to serious, life-threatening complications such as heart failure or irregular heartbeats.

Motor Neurone Disease

A progressive degenerative disorder affecting the nerves causing weakness and wasting of muscles, affecting a person's mobility, limbs, speech, swallowing and breathing.

Multiple Sclerosis

Multiple sclerosis (MS) is a condition that can affect the brain and spinal cord, causing a wide range of potential symptoms, including problems with vision, arm or leg movement, sensation or balance. It's a lifelong condition that can sometimes cause serious disability, although it can occasionally be mild.


Abnormality of the quality and number of blood cells produced in the bone marrow. A severe form of this could eventually evolve into leukaemia.


Cancer of cells in the bone marrow.

Myocardial Infarction


Inflammation of the heart muscle.


A name to describe muscle disease, muscle weakness or dysfunction of muscle tissue due to abnormal muscle fibres and it can be from various causes.


Inflammation of the kidneys. See Chronic Kidney Disease.


Long term damage to the nerve fibres, usually in both hands and/ or both feet, which can be caused by diabetes or various chemical causes.


Condition in which excess body fat has accumulated to such a degree that health could be negatively affected, particularly with regard to cardiovascular diseases, respiratory conditions, diabetes, cancer and osteoarthritis.


A medical device implanted in the body to help regulate the heart rhythm.


Inflammation of the pancreas.

Parkinson’s Disease

A persistent degenerative disease of the central nervous system, affects movement, speech and other functions.


Peak expiratory flow rate, a method of testing for lung function.

Percutaneous Transluminal Coronary Angioplasty (PTCA)

A procedure used to widen blocked or narrowed coronary arteries (the main blood vessels supplying the heart). The term "angioplasty" means using a balloon to stretch open a narrowed or blocked artery. However, most modern angioplasty procedures also involve inserting a short wire mesh tube, called a stent, into the artery during the procedure. The stent is left in place permanently to allow blood to flow more freely.


Inflammation of the membrane that surrounds the heart.

Peripheral Vascular Disease

A condition where there is reduced blood flow to any part of the body other than the brain or heart, most commonly the legs. It is caused by narrow or blocked blood vessels and can cause leg swelling, pain and discomfort which may require surgical treatment.


Pulmonary function test, used to describe a type of test for lung function.


Inflammatory illness of the lungs.

Polycystic Kidney Disease

Progressive genetic disorder of the kidneys causing the formation of multiple cysts and progressive kidney failure.


Blood disorder in which there is an excess of blood cells, can give rise to a risk of clots forming in the blood vessels.

Poor Circulation

Poor circulation happens when there is inadequate or poor blood flow to a certain part of the body. It isn’t a condition itself but can result from a number of other conditions such as diabetes, and peripheral vascular disease as well as lifestyle factors such as obesity and smoking.


The term used to describe an abnormal amount of protein produced in the urine, an indicator of possible kidney disease.

Pulmonary Embolism

A blood clot in the lung.

Raynaud’s Phenomenon

Discoloration, coldness and loss of sensation in the fingers and toes caused by a lack of blood supply.


An abnormal finding in the eyes where damage can occur to the internal blood vessels that supply the retina. Usually it occurs in diabetics or those with high blood pressure.

Rheumatic Fever

An illness affecting joints, skin and the heart. Heart valve tissues may lose their compliance or be subjected to inflammation, scarring and nodules, in some instances causing various types of heart murmurs.

Rheumatoid Arthritis

Chronic autoimmune disorder affecting the joints, causing inflammation and destruction, can necessitate treatment with steroids or even surgery and can seriously impair mobility.


Chronic disease causing hardening of the skin or other organs.

Senile Dementia

Sleep Apnoea

Sleep disorder in which breathing stops during sleep, this puts strain on heart, causes snoring and high blood pressure, often associated with obesity. Treatment often involves use of CPAP (Continuous Positive Airway Pressure) mask and machine to help breathing at night.



Loss of brain functions due to the interruption of blood supply to the brain, due to blockage or bleeding. Depending on which part of the brain is affected, it can temporarily or permanently impair mobility, speech, vision and other functions. A serious stroke can have long lasting effects and the patient's mobility and activities could be compromised. See also TIA.

Subarachnoid Haemorrhage

Supraventricular Tachycardia

Systemic Lupus Erythematosus

Chronic autoimmune disease in which the body's defences attack itself, causing organ failure which can be fatal.


An abnormality of the blood platelets that could cause blood clotting disorders.


Blood clot inside a vein or artery, and depending on where it occurs in the body, can cause a stroke, heart attack or pulmonary embolism.

TIA, Transient Ischaemic Attack (‘mini-stroke’)

Temporary disturbance in the blood supply to the brain, causing symptoms which pass within 24 hours. No permanent neurological damage occurs.


A test used in those experiencing chest pain to evaluate the likelihood that there could be a heart attack in progress.


Infectious bacterial disease affecting the lungs and sometimes other organs, causing chronic cough, fever, weight loss, can be fatal.

Ulcerative Colitis

An inflammatory bowel disease. Some forms of ulcerative colitis can also affect other parts of the body and may necessitate surgery.

Von Willebrand Disease

A common inherited condition that can make you bleed more easily than normal.

Waldenstrom Macroglobulinaemia

A type of cancer of white blood cells.

Wegener’s Granulomatosis

A condition which causes inflammation of the blood vessels, causing failure of the lungs, kidneys and other major organs.

Wolff-Parkinson-White syndrome

A disorder of the electrical activity in the heart which can cause fainting, arrhythmia and blood clots.