Brain tumours
Anything that can increase your risk of getting a disease is called a risk factor. There are some risk factors for brain tumours. Experts decide on a risk factor after studying the population and specifically looking at groups of people who have this cancer. It’s not usually possible to say what has caused cancer in an individual.
Many people who have these risk factors never get it. And some people with none of the risk factors can still develop it.
Brain tumours can start at any age. But as we get older, our risk of developing most cancers, including brain tumours, increases.
In the UK, the risk of brain tumours is greatest in those aged between 85 and 89 years.
Being overweight or obese increases the risk of some cancer types, including a type of brain tumour called meningioma. About 2 out of 100 primary brain tumours (about 2%) diagnosed in the UK every year are caused by being overweight or obese.
We know it can be difficult to keep a healthy weight. Lots of things can impact our weight. We have information to help keep a healthy weight by keeping physically active and eating a healthy, balanced diet.
Find out more about obesity, weight and cancer
Ionising radiation is a type of radiation used by some medical scans, such as x-rays and CT scans. These scans are important to help diagnose many illnesses, including cancer.
Less than 1 out of every 100 primary brain tumours (less than 1%) diagnosed in the UK are caused by ionising radiation. The risks of radiation from medical scans are very low. Your doctors and dentist will keep your exposure to radiation as low as possible. They will only do x-rays and CT scans when they are necessary.
Find out more about x-rays, radiation and your risk of cancer
Your risk is slightly higher than other people in the general population if you have a close relative who has had a brain tumour. A close relative is a parent, sibling or child.
A small proportion of brain tumours are linked to known inherited genetic conditions. People who have one of these rare conditions or syndromes have an increased risk of developing certain types of brain tumours.
There are several syndromes, including:
neurofibromatosis (NF) type 1 and type 2
tuberous sclerosis (TSC)
Li-Fraumeni syndrome
Von Hippel-Lindau syndrome (VHL)
Turner syndrome
Turcot syndrome
Gorlin syndrome
If you have one of these conditions or you are worried about an inherited condition, talk to your doctor. They can help you understand what it may mean for you and discuss your risk.
Find out more about inherited cancer genes
Several studies have looked at whether substances or chemicals used in some workplaces increase the risk of brain tumours. The evidence is limited, and any possible risk is thought to be very small.
Go to the Cancer Statistics section
There are ways you can reduce your risk of cancer in general.
Find out more about how you could reduce your risk of cancer
Stories about potential causes are often in the media and it isn’t always clear which ideas are supported by evidence. There might be things you have heard of that we haven’t included here. This is because either there is no evidence about them or it is less clear.
Last reviewed: 29 Sept 2026
Next review due: 29 Sept 2029
Common symptoms of brain tumours include headaches, feeling or being sick and seizures (fits).
You usually start by seeing your GP who might refer you to a specialist. Or you might go to Accident and Emergency (A&E) if you suddenly have severe symptoms.
There are many different types of brain tumours. They are usually named after the type of cell they develop from.
Treatment for a brain or spinal cord tumour depends on the type of tumour you have, where it is and your general health.
Primary brain tumours are cancers that start in the brain.
