Certain conditions can increase your risk of stroke. Some risk factors are treatable and others are not. By treating the conditions you can, with lifestyle changes, medicines, or surgery, you can lower your risk.
Risk Factors That Can Be Treated
High blood pressure (hypertension). High blood pressure is the most important risk factor for stroke. According to the American Heart Association, high blood pressure affects about 1 in 3 American adults. It usually has no symptoms. In fact, most people do not know that they have high blood pressure until they have a stroke or heart attack. Controlling high blood pressure reduces the risk of stroke. Exercise, a healthy diet, and medicines can often control high blood pressure.
Heart disease. People with heart disease (such as coronary artery disease, damaged heart valves, heart rhythm problems)have twice the risk of stroke that people with healthy hearts do. Controlling the three major risk factors for heart disease—cigarette/tobacco smoking, high blood cholesterol, and high blood pressure—can also reduce the risk of stroke.
Atherosclerosis. Often called "hardening of the arteries," atherosclerosis is a condition in which fatty materials, cholesterol, and calcium build up on the inside walls of the arteries, blocking blood flow.
High red blood cell count. Even a moderate elevation in red blood cell count can be a risk factor for stroke. A high number of red blood cells thickens the blood, leading to blood clots.
Transient ischemic attacks (TIAs). TIAs usually happen when a blood clot temporarily blocks an artery in the brain or neck. This keeps part of the brain from getting the blood it needs. TIAs are a warning sign of a possible stroke. Of those who have had one or more TIAs, more than a third will have a stroke. The symptoms are similar to those of a major stroke. See a doctor right away if you or someone you know has any of the symptoms of a TIA.
Sleep apnea. OSA (obstructive sleep apnea) is a major risk factor for stroke because it increases blood pressure and lowers oxygen in the blood.
Patent foramen ovale (PFO). A PFO is an opening between the left and right atria (the upper chambers) of the heart. Everyone has a PFO before birth, but it usually closes shortly after birth. Doctors think that older people who also have a PFO may have a greater risk of stroke from blood clots that may pass through the opening.
Risk Factors That Cannot Be Changed
Age. The risk of stroke increases with age. From age 55 onward, your chances of having a stroke more than double every ten years.
Gender. The incidence of stroke is higher for men than for women.
Race. African Americans have a higher risk of stroke than Caucasians do.
Diabetes. Although diabetes can be controlled, people with the disease are still more likely to have a stroke. The incidence of stroke is greater for women who have diabetes than for men who have diabetes.
Prior stroke. The risk of stroke increases greatly for a person who has already had a stroke. If a person has had a heart attack, he or she is also at higher risk of having a stroke.
Heredity. The risk of stroke is greater in people who have a family history of stroke and TIAs.
Carotid bruit. A bruit (pronounced bru-ee) generally means atherosclerosis is present. A bruit is an abnormal sound heard when a stethoscope is placed over a blocked artery, in this case the carotid artery in the neck. A carotid bruit most often means an increased risk for stroke.
Carotid artery disease. Fatty deposits found in the carotid artery (the main artery between the heart and brain) could block this important blood supply. Depending on the amount of blockage, surgery may be needed to remove buildup in the artery.
Lifestyle Habits that Increase Stroke Risk
These factors indirectly increase the risk of stroke. Changing lifestyle habits can prevent or greatly lower the risk of stroke.
Smoking. According to the National Stroke Association, smoking doubles the risk for stroke.
Heavy alcohol use. Drinking alcohol is recommended only in moderation. The American Heart Association suggests that moderate alcohol intake is an average of one to two drinks per day for men and one drink per day for women. One drink is defined as 1½ fluid ounces (fl oz) of 80-proof spirits, 4 fl oz of wine, or 12 fl oz of beer. Drinking more than this amount per day increases the risk of high blood pressure and can lead to stroke.
Illegal drug use. Intravenous drug users have a higher risk of stroke. Cocaine use has also been linked to strokes and heart attacks.
Physical inactivity. Inactivity is not only a major risk factor for developing coronary artery disease, but it can also lead to high blood pressure, low levels of high-density lipoproteins (HDL or "good cholesterol"), and diabetes. Exercising 30 to 40 minutes at least 3 to 4 times a week can help improve many conditions.
Obesity. Being obese doubles your chance for developing high blood pressure, a major risk factor for stroke. .
Birth control pills (oral contraceptives). Birth control pills alone are a low-level risk factor. But if birth control pills are combined with certain other risk factors, such as smoking, the risk of stroke increases.
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Updated January 2015