A brain tumour is a growth of cells in the brain that multiplies in an abnormal, uncontrollable way. It can either be cancerous (malignant) or non-cancerous (benign). Brain tumours are graded from 1 to 4 according to their behaviour, such as how fast they grow and how likely they are to grow back after treatment. benign brain tumours are low grade (grade 1 or 2), which means they grow slowly and are less likely to return after treatment malignant brain tumours are high grade (grade 3 or 4) and either start in the brain (primary tumours) or spread into the brain from elsewhere (secondary tumours); they're more likely to grow back after treatment This page gives general information relevant to both types of brain tumour. Symptoms of a brain tumour The symptoms of a brain tumour vary depending on the exact part of the brain that's affected. Common symptoms include: severe, persistent headaches seizures (fits) persistent nausea, vomiting and drowsiness mental or behavioural changes, such as memory problems or changes in personality progressive weakness or paralysis on one side of the body, vision problems, or speech problems Sometimes, you may not have any symptoms to begin with, or they may only develop very slowly over time.