Brain tumours - benign or malignant

Generally, brain tumours can be benign (non cancerous) or malignant (cancerous). Benign tumours usually grow slowly. They are less likely to come back after treatment or to spread to other parts of the brain. Your doctor might refer to some benign brain tumours as low grade. The brain is made of different tissues and cells which can develop into different types of tumours.


There are over 130 different types of brain tumours. Tumours can start in any part of the brain or spinal cord. They are usually named after the type of cell they develop from. The most common type of brain tumours in adults is called glioblastoma multiforme (GBM) and this is malignant. This is different from cancers that have spread to the brain from somewhere else in the body. These are called secondary brain cancers or brain metastases.


Brain tumours cause symptoms because:

  • they take up space inside the skull when they grow
  • of their position in the brain

The symptoms can develop gradually over some months or even years if the tumour is slow growing. Or quickly over days or weeks if the tumour is fast growing. Your skull is made of bone, so there's a fixed amount of space for the brain to take up. If there's a growing tumour, it increases the pressure inside the skull. This is called raised intracranial pressure.

Headaches are a common symptom of illness. It's unlikely that you have a brain tumour if headaches are your only symptom. But see a doctor if you have headaches:

  • with feeling or being sick
  • when you didn't have them before
  • that wake you up at night
  • with eye problems such as seeing flashing lights or blind spots
  • that got steadily worse over a period of weeks or months

Seizures happen in up to 8 out of every 10 people (up to 80%) with a brain tumour. You might have some jerking or twitching of your hands, arms or legs. Or your seizure might affect your whole body. Having a seizure is very frightening. Different illnesses can cause seizures and it is important that you see your doctor immediately or go to A&E if you have one. You might feel or be sick, especially when you move suddenly. It’s rare for people with a brain tumour to have sickness on its own. You may have sickness with headaches, weakness and problems with your eyes. You might feel drowsy or even lose consciousness. This might happen because raised intracranial pressure can lower the blood supply to the brain. This can be frightening for you and the people around you. You might find that your eyesight is getting worse and glasses are not helping. Or your vision comes and goes. You might lose the ability to see out of the corner of your eyes, making you bump into cars or objects on your left or right side.

You may also have:

  • blurred vision
  • floating shapes
  • tunnel vision

Personality and behaviour changes

You, or the people around you, might notice that you are confused or that your personality has changed. You may also find it difficult to think normally.