Stroke, or cerebrovascular accident, occurs when the blood supply to the brain is interrupted or reduced. That is, a rapid loss of brain function due to disturbance in the blood supply to the brain. The compromise of the blood supply to the brain deprives the brain of oxygen and nutrients, which can cause the brain cells to die.

The disturbance of the blood supply to the brain can be as a result of reduced or blockage of blood flow, called ischemic stroke or bleeding into the brain as a result of a leaking or burst blood vessels called haemorrhagic stroke.

Stroke can occur as a result of lack of blood flow to a particular area of the brain (ischemic) or bleeding into an area of the brain (haemorrhagic). As a result, the affected area of the brain cannot function; which might result in an inability to move one or more limbs on one side of the body, inability to understand or formulate speech or inability to see one side.[http://www.standtimes.com/index.php?option=com_content&view=category&layout=blog&id=43&Itemid=73]