Medical terms explained

Doctors may use unfamiliar words that you don’t understand. Here are some of the most common ones explained (alphabetically).

If you don’t understand the words a doctor or nurse uses at any time, don’t feel embarrassed to ask them to explain them to you.

Alopecia
Hair loss

Anaemia
A reduced number of red blood cells

Anaesthetic
Drugs that put a person to sleep (general anaesthetic) or that numb a part of the body (local anaesthetic) while they have an operation or procedure

Benign 
Describes a tumour or growth that is not cancerous but may still be capable of causing problems

Biopsy 
A small sample of tissue taken from the body to make a diagnosis

Blood count 
A blood test to check the number of different cells in the blood (sometimes called a full blood count or FBC)

Bone marrow 
The spongy material in the centre of the large bones of the body, which makes blood cells

Cardio 
To do with the heart

Catheter 
A thin, flexible tube used to give fluid into the body or to drain fluid from the body (for example, a urinary catheter or a central venous catheter)

Cerebrospinal fluid (CSF) 
Fluid produced in the brain that surrounds the brain and spinal cord

Chemotherapy 
Drug treatment that kills cancer cells

Chromosome 
Structure in the nucleus of the cell that contains the genes

Congenital 
Any condition existing at birth

Cytogenetics 
The study of chromosomes in cells

Electrolytes 
The minerals and salts in the body – for example, sodium, potassium and calcium

Endocrine 
To do with hormones

Excision 
Cutting out

Genetic 
A condition caused by abnormal genes (may be inherited)

Haematology 
The study of blood and blood disorders

Haemoglobin 
The substance in red blood cells that carries oxygen around the body

Histopathology 
The study of body tissues

Hormone
A substance made and secreted by a gland and carried in the bloodstream to parts of the body where it has a specific effect on the way the body works

Immune system 
The body’s defence against infection, disease and foreign substances

Immunology 
The study of the body’s immune system, which fights infection

Immunophenotyping 
A test to identify particular proteins in the cells to help find out which type of cell has become cancerous.

Immunosuppressive
Lowering the body’s ability to fight infection

Intravenous (IV)
Into a vein

Lymph
A clear fluid that’s part of the body’s defence against infection. It’s carried around the body in a network of lymphatic vessels

Lymphocyte 
A type of white blood cell that fights infection

Malignant 
Describes a tumour or growth that is cancerous. If a tumour is malignant it grows uncontrollably and can travel to other parts of the body

Metastases 
Tumours that have spread from the first (primary) tumour into another part of the body. Also known as secondary tumours

Microbiology 
The study of germs

Nausea 
Feeling sick

Neuro 
To do with the nerves or nervous system

Neutropenia or neutropenic
Low levels of neutrophils

Neutrophils
White blood cells that fight infection

Oncology 
The study and treatment of cancer

Opthalmology
The study of the eyes

Oral 
To do with the mouth

Osteo 
To do with the bones

Paediatric 
To do with children

Palliative 
Relief of a symptom (for example, pain) rather than cure of the disease

Platelet 
A type of blood cell that helps the blood to clot

Prognosis
The expected outcome of a disease and its treatment

Prosthesis 
An artificial replacement of something – for example, a bone

Pulmonary 
To do with the lungs

Radiotherapy 
The use of high-energy x-rays to destroy cancer cells

Refractory 
Resistant to treatment

Relapse 
The return of a disease after previous treatment

Remission 
There is no evidence of the disease using the available tests

Renal 
To do with the kidneys

Stem cell 
Early (immature) blood cell from which other blood cells are made

Subcutaneous 
Under the skin

Therapy
Treatment

Thrombocytopaenia 
Low levels of platelets in the blood