A stroke happens when part of the brain is damaged or destroyed due to an interruption of its blood supply. At this time brain cells are deprived of oxygen and other vital nutrients. Some brain cells will be damaged and others will die.
A stroke is also referred to as a cerebrovascular accident, (CVA). The term "stroke" comes from the fact that it usually happens without any warning - "striking" the person out of the blue.
A stroke is to the brain what a heart attack is to the heart.
Approximately 80% of strokes happen when a blood clot blocks one of the arteries carrying blood to the brain. This type of stroke is referred to as an Ischaemic Stroke. Ischaemia means "lack of blood" to body tissue.
About 20% of strokes are caused by bleeding from a burst blood vessel. This is known as a Haemorrhagic Stroke, as haemorrhage means "escape of blood" from its vessel.
Different Types of Stroke