A stroke is a sudden interruption of blood flow to any part of your brain, causing damage and death to brain cells. Its effects can be devastating and may last a lifetime. In more developed countries such as New Zealand, after cardiovascular disease and cancer, stroke is the third most common cause of hospitalisation and death. 

A stroke is also known as a cerebrovascular accident (CVA), and can be a life-threatening event in which the brain is not getting enough oxygen. It may be due to either a prolonged lack of oxygen-rich blood to the brain (cerebral ischaemia), or bleeding into or around the brain (cerebral haemorrhage). Like any other part of the body, your brain needs a constant supply of blood and oxygen for it to work properly. Find out more and prevention in the main article.