A benign (non-cancerous) brain tumour is a mass of cells that grows slowly in the brain. It usually stays in one place and does not spread.
Generally, brain tumours are graded from 1 to 4 according to their behaviour, such as how fast they grow and how likely they are to spread. Grade 1 tumours are the least aggressive and grade 4 are the most harmful and cancerous. Cancerous tumours are described as malignant.
Low-grade brain tumours – grades 1 or 2 – tend to be slow growing and unlikely to spread, so they're usually classed as benign.
These pages focus on low grade brain tumours. For information about brain tumours graded 3 or 4, read high-grade (malignant) tumours.
What are the symptoms?
The symptoms of a low-grade or benign brain tumour depend on how big it is and where it is in the brain. Some slow-growing tumours may not cause any symptoms at first.
Eventually, the tumour can put pressure on the brain and may cause headaches and seizures (fits). The tumour 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.
Read more about the symptoms of a benign brain tumour.
Who is affected?
Brain tumours can affect people of any age, including children.
There are about 4,300 people diagnosed with benign brain tumours in the UK each year. The majority of these are low-grade gliomas, a type of tumour that starts in the supportive tissue of the brain.
Although the cause of most benign brain tumours is not known, it is thought that certain genetic conditions and previous radiotherapy treatment to the head may increase the risk of one developing.
Read more about the possible causes of benign brain tumours.
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.
Many benign brain tumours can be surgically removed and don't come back once they have been removed, causing no further problems. However, grade 2 gliomas will often grow back after treatment and have the potential to change into high-grade or malignant (cancerous) tumours, which are fast-growing and likely to spread. This change is called mutation.
Your treatment will depend on the type and location of the tumour, and your outlook will depend on whether the tumour grows back and whether it mutates (changes).
Read more information about treating a benign brain tumour.
After treatment, several types of therapy are available to help you recover.
Your doctor can refer you to a counsellor if you want to talk about the emotional aspects of diagnosis and treatment. There are also many organisations and helplines, such as Brain Tumour UK, that provide information and support.
Read more about recovering from treatment for a benign brain tumour.