Symptoms and causes of primary brain tumours

This section is for teenagers and young adults. It is about the symptoms and causes of tumours that start in the brain (called primary brain tumours).

We have information for people of all ages about brain metastases. These are tumours that start somewhere else in the body and spread to the brain.

Signs and symptoms

A brain tumour can cause different symptoms depending on where it is in the brain. Some possible symptoms are:

  • changes in your balance and walking
  • weakness down one side of the body
  • problems with speech
  • changes in personality, thinking or behaviour
  • seizures (fits)
  • sight problems, including blurred vision, double vision, loss of eyesight or abnormal eye movements
  • delayed puberty.

Sometimes, a tumour can increase pressure inside the skull. This is called raised intracranial pressure. It can also cause symptoms including:

  • headaches
  • sickness and vomiting
  • confusion
  • problems controlling when you need to pee (wetting yourself).

Other conditions can cause these symptoms. But you should visit your GP if you have any of these symptoms or are worried about brain tumours. They will talk to you about your symptoms. They can arrange for you to have tests or to see a specialist doctor if needed.


We do not know what causes most brain tumours, but research is going on to try to find out. Remember, it is not anything that you have done.

Rare genetic conditions that run in families can increase your risk of a brain tumour. We have more information about this in our general information on genetic conditions and inherited cancers. This is written for people of all ages.

People who have radiotherapy to the head as children are at slightly higher risk of brain tumours later in life.

Mobile phones, power lines and viruses have all been suggested as possible causes of brain tumours. But no research has found any strong evidence to link any of these to brain tumours.

Our general primary brain tumour section has more information written for all ages. The Children’s Cancer and Leukaemia Group has information about brain tumours in children.

Back to Brain tumours