This blockage leads to a sudden partial loss of brain function. Without oxygen and important nutrients, the affected brain cells are either damaged or die within a few minutes.

There are three main types of strokes: thrombotic, embolic and hemorrhagic. * A thrombotic stroke is caused by fatty deposits called plaques that have built up in the arteries carrying blood to the brain. These deposits slows the blood flow until a blood clot completely blocks the artery and the flow of oxygen and nutrients to the brain. * An embolic stroke is caused by a blood clot formed in another part of the body that breaks loose, travels through the bloodstream, and blocks an artery carrying oxygen and nutrients to the brain. When traveling through the body the blood clot is called an embolus. A hemorrhagic stroke is caused when an artery supplying blood bleeds into the brain. The broken blood vessel prevents needed oxygen and nutrients from reaching the brain cells. One type of hemorrhagic stroke is caused when an artery that has weakened over time bulges (called an aneurysm) and suddenly breaks.

Other symptoms include blurred vision, difficulty talking, stumbling and/or sudden clumsiness. Sometimes a mini-stroke, which lasts only a few moments and is called a transient ischemic attack (TIA), comes before a stroke.

Time is critical for stroke patients: You should seek immediate medical care. Research shows that treatment during the first hours after symptoms appear can be important for the best possible recovery. An emergency doctor or neurologist (a doctor who diagnoses and treats disorders of the brain and nervous system) will provide emergency treatment. Then a family doctor, internist, or geriatrician can step in and provide long-term care.

But the conditions leading to a stroke develop over many years. Risk factors or conditions that may lead to stroke include high blood pressure, smoking, heart disease, and diabetes. The risk of stroke increases with age and is higher in blacks and Hispanics than in whites.

Have your blood pressure checked often, and, if it is high, follow your doctor's advice on how to lower it. Treating high blood pressure reduces the risk for both stroke and heart disease. Cigarette smoking is linked to increased risk for stroke. Research shows that the risk of stroke for people who have quit smoking for 2 to 5 years is lower than for smokers.

Researchers think that exercise may make the heart stronger and improve circulation. It also helps control weight. Being overweight increases the chance of high blood pressure, atherosclerosis, heart disease, and adult-onset (type II) diabetes. Physical activities like brisk walking, cycling, swimming, and yard work lower the risk of both stroke and heart disease. Talk with your doctor before starting an exercise program.

For some patients, recovery occurs within weeks following a stroke; for others, it may take many months or years. Stroke rehabilitation includes many kinds of therapies: physical therapy to strengthen muscles and improve balance and coordination; speech and language therapy; and occupational therapy to improve eye-hand coordination and skills needed for tasks such as bathing and cooking.