Stroke is a leading cause of death and a leading cause of serious, long-term disability, according to the American Heart Association (AHA) and the American Stroke Association (ASA). The ASA reports that strokes are the fifth leading cause of death in the U.S.
What is a stroke?
A stroke occurs when the flow of oxygen-rich blood is blocked to a portion of the brain. The brain needs a constant supply of oxygen and nutrients in order to work well. If blood supply is stopped even for a short time, this can cause brain cells to die. Also, sudden bleeding in the brain can cause a stroke. The two main types of stroke are ischemic and hemorrhagic. Click here to learn more.
What is an ischemic stroke?
An ischemic stroke occurs when a blood vessel that supplies the brain becomes blocked or "clogged" and impairs blood flow to part of the brain. The brain cells and tissues begin to die within minutes from lack of oxygen and nutrients. The area of tissue death is called an infarct. About 87% of strokes fall into this category.
What is a hemorrhagic stroke?
Hemorrhagic strokes occur when a blood vessel that supplies the brain ruptures and bleeds. When an artery bleeds into the brain, brain cells and tissues do not receive oxygen and nutrients. In addition, pressure builds up in surrounding tissues and irritation and swelling occur, which can lead to further brain damage. About 13% of strokes are caused by hemorrhage.
What are TIAs (transient ischemic attacks)?
A transient ischemic attack (TIA), also called a ministroke or warning stroke, causes symptoms similar to those of a stroke. The difference is that TIAs don’t cause permanent brain damage. TIAs happen when a blood clot or artery spasm suddenly blocks or closes off an artery briefly. This stops blood from reaching a part of the brain for a short period of time. A TIA is a medical emergency and you should call 911, even if your symptoms resolved.