Having a stroke is one of the most frightening prospects of aging. Strokes can come on suddenly, stealing the use of an arm or the ability to speak. A stroke can be fatal or leave us permanently disabled.
Although most strokes are survivable, most people never recover completely after a stroke. Around a quarter of those who survive are permanently disabled.
There are two main types of strokes:
Ischemic: An artery inside or leading to the brain becomes completely blocked. Usually this is caused by a blood clot that forms in a clogged artery. It can also be due to a blood clot traveling to the brain from the heart.
Most strokes (about 87%) are ischemic, and most of those are caused by atherosclerosis.
Hemorrhagic: These strokes are caused by bleeding into the brain. Most commonly, high blood pressure causes a small artery to burst open. Abnormal blood vessels (such as aneurysms and arteriovenous malformations) are particularly likely to rupture. The bleeding disrupts healthy blood flow to brain tissue.
Hemorrhagic strokes are less common, making up about 13% of all strokes.
Regardless of whether a stroke is caused by atherosclerosis or bleeding, the symptoms are the same:
Sudden weakness on one side (in the face, arm, or leg)