Main ContentWhat is a stroke?
A stroke occurs when blood flow to the brain is interrupted. It is a medical emergency. As blood flow stops, the area in the brain affected by the stroke loses oxygen and nutritional support, and brain cells begin to die. This can result in long-term disability or even death.
There are two types of stroke:
An ischemic stroke occurs when blood flow to the brain is blocked, most commonly by blood clots. Often these clots form somewhere else in the body, such as the heart, and travel through the blood vessels to the brain where they become lodged. Ischemic strokes account for about 87% of all strokes.
A hemorrhagic stroke occurs when an area in the brain suddenly begins to bleed due to a ruptured or leaking blood vessel. Cerebral aneurysms can be a cause of bleeding in the brain. An aneurysm can be compared to a balloon. Instead of being filled with air, however, it is filled with blood. They form when a blood vessel has a thin or weakened area. The force of blood flowing over the weak spot causes it to bulge out and begin filling with blood. Aneurysms often develop slowly, but over time they can grow to a point where they burst.