A brain tumour is a growth of cells in the brain which multiply in an abnormal, uncontrollable way.
A benign brain tumour is a non-cancerous growth. It usually grows slowly in one place and does not invade other areas of the brain or spread to other parts of the body. It is an uncommon condition.
There are different types of benign brain tumour, depending on the type of brain cells they have grown from (see box, left).
The cause of benign brain tumours is often unknown, although a genetic disease, such as neurofibromatosis, can increase your risk of getting one (see Causes).
Radiotherapy to the brain, used to treat childhood leukaemia, can also increase the risk. Around five in 100 people with a benign brain tumour have a family history of brain tumours.
Who is affected?
Brain tumours can affect people of any age, including children. Some benign brain tumours, such as meningiomas, are more common in women.
What are the symptoms?
A benign brain tumour can put pressure on the brain, causing symptoms such as irritability, headache and vomiting. It can also prevent an area of the brain from functioning properly. For example, a tumour in the occipital lobe (at the back of the brain) may cause loss of vision on one side. See Symptoms for more information.
Outlook
Benign brain tumours can be serious if they are not diagnosed and treated early. Although they remain in one place and do not usually spread, they can cause harm by pressing on and damaging nearby areas of the brain.
Some benign brain tumours can be surgically removed. Tumours do not normally come back once they have been removed and no further problems are caused.