In England, strokes are a major health problem. Every year over 150,000 people have a stroke and it is the third largest cause of death, after heart disease and cancer. A stroke is a serious medical condition that occurs when the blood supply to part of the brain is cut off. Strokes are a medical emergency and prompt treatment is essential because the sooner a person receives treatment for a stroke, the less damage is likely to happen. The brain damage caused by strokes means that they are the largest cause of adult disability in the UK.