A stroke, sometimes called a "brain attack," occurs when blood flow to an area in the brain is cut off. The brain cells, deprived of the oxygen and glucose needed to survive, die. If not caught early, permanent brain damage and death can result.
Atherosclerosis -- hardening and narrowing of the arteries -- gets a lot of bad press but with good reason. This progressive process silently and slowly blocks arteries, putting blood flow at risk.
Atherosclerosis is the usual cause of heart attacks, strokes, and peripheral vascular disease -- what together are called "cardiovascular disease." Cardiovascular disease is the No. 1 killer in America, with more than 800,000 deaths in 2005.
How does atherosclerosis develop? Who gets it, and...
Ischemic stroke is similar to a heart attack, except it occurs in the blood vessels of the brain. Clots can form either in the brain's blood vessels, in blood vessels leading to the brain, or even blood vessels elsewhere in the body that travel to the brain. These clots block blood flow to the brain's cells. Ischemic stroke can also occur when too much plaque (fatty deposits and cholesterol) clogs the brain's blood vessels. About 80% of all strokes are ischemic.
Hemorrhagic (heh-more-raj-ik) strokes occur when a blood vessel in the brain breaks or ruptures. The result is blood seeping into the brain tissue, causing damage to brain cells. The most common causes of hemorrhagic stroke are high blood pressure and brain aneurysms. An aneurysm is a weakness or thinness in the blood vessel wall.
What Are the Symptoms of Stroke?
The most common symptoms of a stroke are:
Weakness or numbness of the face, arm, or leg on one side of the body
Loss of vision or dimming (like a curtain falling) in one or both eyes
Loss of speech, difficulty talking, or understanding what others are saying