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 can result.
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 which then 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 of this nature.
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 a 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.