A stroke occurs when the blood flow to the brain is interrupted or cut-off. When this happens, the affected area of the brain does not receive the oxygen and nutrients that it needs. An ischemic stroke is the most common type of stroke and is caused by a blockage in an artery leading to the brain. A blocked artery will cut-off blood supply to a region of the brain. If the blood supply is blocked for more than a few minutes, brain cells will begin to die.
The two types of ischemic strokes are thrombotic and embolic. These terms refer to the location of the blood clot. In a thrombotic stroke, a blood clot forms in one of the blood vessels in the brain. In an embolic stroke, a blood clot forms elsewhere in the body, such as in the heart, and then travels to the brain to cause a blockage.
Ischemic strokes have many potential causes. Excessive blood cholesterol will cause the arteries to narrow and eventually become blocked—resulting in a thrombotic stroke. Blood clots that form in the heart are another cause of ischemic strokes. This occurs when blood clot forms in the heart and then travels to the head, blocking blood supply to the brain. This type of stroke would be an embolic stroke. Blood clots in the heart are more likely to form in people who have irregular heartbeats, have had a heart attack, or have diseased heart valves. Other causes of ischemic strokes include street drug use, traumatic injury to the blood vessels of the neck, and blood clotting disorders.
The risk for stroke is higher in older adults, women, and individuals of African heritage. Other risk factors include high blood pressure, heart disease, smoking, or diabetes. Emergency personnel should be called immediately if you think that you or someone around you is experiencing a stroke. There are a number of complications that can occur after a stroke. Support groups are a great resource for more information and resources.