A stroke is caused by an interruption in blood supply to an area of the brain. The brain is very sensitive to any interruption in blood flow. Brain cells begin to die within minutes of losing their supply of oxygen and glucose. The interruption of blood flow can occur by one of two mechanisms.

Stroke mechanisms:

• Hemorrhagic stroke:
• Caused by bleeding in the brain.
• Ischemic stroke:
• Caused by blockage of the arteries supplying the brain.
• Ischemic strokes are usually caused by blood clots or the progressive effects of atherosclerosis.