A stroke, or “brain attack,” occurs when blood circulation to the brain fails. Brain cells can die from decreased blood flow and the resulting lack of oxygen.
There are two broad categories of stroke:
- Those caused by a blockage of blood flow
- Those caused by bleeding into the brain.
A blockage of a blood vessel in the brain or neck, called an ischemic stroke, is the most frequent cause of stroke and is responsible for about 80 percent of strokes. These blockages stem from three conditions: the formation of a clot within a blood vessel of the brain or neck, called thrombosis; the movement of a clot from another part of the body such as the heart to the brain, called embolism; or a severe narrowing of an artery in or leading to the brain, called stenosis. Bleeding into the brain or the spaces surrounding the brain causes the second type of stroke, called hemorrhagic stroke.
Two key steps you can take will lower your risk of death or disability from stroke: control stroke’s risk factors and know stroke’s warning signs
Stroke is the fourth leading cause of death among Americans, and a much larger contributor to chronic disability and health care costs than this ranking suggests. There’s no question that preventing strokes is important. But a big question is how best to do so and in whom.
Warning Signs of a Stroke
Warning signs are clues your body sends that your brain is not receiving enough oxygen. If you observe one or more of these signs of a stroke or “brain attack,” don’t wait, call a doctor or 911 right away!
- Sudden numbness or weakness of face, arm, or leg, especially on one side of the body
- Sudden confusion, or trouble talking or understanding speech
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, or loss of balance or coordination
- Sudden severe headache with no known cause
Other danger signs that may occur include double vision, drowsiness, and nausea or vomiting. Sometimes the warning signs may last only a few moments and then disappear. These brief episodes, known as transient ischemic attacks or TIAs, are sometimes called “mini-strokes.” Although brief, they identify an underlying serious condition that isn’t going away without medical help. Unfortunately, since they clear up, many people ignore them. Don’t. Paying attention to them can save your life.
Risk Factors for a Stroke
A risk factor is a condition or behavior that occurs more frequently in those who have, or are at greater risk of getting, a disease than in those who don’t. Having a risk factor for stroke doesn’t mean you’ll have a stroke. On the other hand, not having a risk factor doesn’t mean you’ll avoid a stroke. But your risk of stroke grows as the number and severity of risk factors increases.
Some factors for stroke can’t be modified by medical treatment or lifestyle changes.
- Age. Stroke occurs in all age groups. Studies show the risk of stroke doubles for each decade between the ages of 55 and 85. But strokes also can occur in childhood or adolescence. Although stroke is often considered a disease of aging, the risk of stroke in childhood is actually highest during the perinatal period, which encompasses the last few months of fetal life and the first few weeks after birth.
- Gender. Men have a higher risk for stroke, but more women die from stroke. Men generally do not live as long as women, so men are usually younger when they have their strokes and therefore have a higher rate of survival.
- Family history of stroke. Stroke seems to run in some families. Several factors may contribute to familial stroke. Members of a family might have a genetic tendency for stroke risk factors, such as an inherited predisposition for high blood pressure (hypertension) or diabetes. The influence of a common lifestyle among family members also could contribute to familial stroke.
People with healthy blood pressure—less than 120/80—have about half the lifetime risk of stroke as those with high blood pressure, or hypertension. “High blood pressure damages blood vessels throughout the body, making them more susceptible to developing clots,” says Lewis Morgenstern, MD, director of the University of Michigan Stroke Program.
Women over 55 are significantly more likely than men to develop hypertension, perhaps because they’ve lost whatever protective effects estrogen might have provided. Here’s how to keep your blood pressure in the safe zone.
Up to 80 percent of all strokes can be prevented—start reducing risk now.
Although stroke can happen to anyone, certain risk factors can increase chances of a stroke. However, studies show that up to 80 percent of strokes can be prevented by working with a healthcare professional to reduce personal risk. It is important to manage personal risk and know how to recognize and respond to stroke signs and symptoms. Learn interactively about more than 20 leading risk factors for stroke through the interactive risk factor tool.