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.
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 in young and middle age, but rates even out at older ages, and 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.
Race. People from certain ethnic groups have a higher risk of stroke. For African Americans, stroke is more common and more deadly—even in young and middle-aged adults—than for any ethnic or other racial group in the United States. Studies show that the age-adjusted incidence of stroke is about twice as high in African Americans and Hispanic Americans as in Caucasians, and while stroke incidence has declined for whites since the 1990s, there has not been a decline for Hispanics or black Americans. An important risk factor for African-Americans is sickle cell disease, which can cause a narrowing of arteries and disrupt blood flow. The incidence of the various stroke subtypes also varies considerably in different ethnic groups.
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.
High blood pressure, or hypertension. Hypertension is by far the most potent risk factor for stroke. Hypertension causes a two-to four-fold increase in the risk of stroke before age 80. If your blood pressure is high, you and your doctor need to work out an individual strategy to bring it down to the normal range.
Cigarette smoking. Cigarette smoking causes about a two-fold increase in the risk of ischemic stroke and up to a four-fold increase in the risk of hemorrhagic stroke. It has been linked to the buildup of fatty substances (atherosclerosis) in the carotid artery, the main neck artery supplying blood to the brain. Blockage of this artery is the leading cause of stroke in Americans. Your doctor can recommend programs and medications that may help you quit smoking. By quitting, at any age, you reduce your risk of lung disease, heart disease, and a number of cancers.
Heart disease. Common heart disorders such as coronary artery disease, valve defects, irregular heart beat (atrial fibrillation), and enlargement of one of the heart’s chambers can result in blood clots that may break loose and block vessels in or leading to the brain. Atrial fibrillation—which is more prevalent in older people—is responsible for one in four strokes after age 80, and is associated with higher mortality and disability.
Warning signs or history of TIA or stroke. If you experience a TIA, get help at once. If you’ve previously had a TIA or stroke, your risk of having a stroke is many times greater than someone who has never had one. If you have had a stroke in the past, it’s important to reduce your risk of a second stroke. Your brain helps you recover from a stroke by asking the unaffected brain regions to do double duty. That means a second stroke can be twice as bad.
Diabetes. In terms of stroke and cardiovascular disease, having diabetes is the equivalent of aging 15 years. You may think this disorder affects only the body’s ability to use sugar, or glucose. But it also causes destructive changes in the blood vessels throughout the body, including the brain. If blood glucose levels are high at the time of a stroke, brain damage is usually more severe and extensive than when blood glucose is well-controlled. Hypertension is common among diabetics and accounts for much of their increased stroke risk. Treating diabetes can delay the onset of complications that increase the risk of stroke.
Cholesterol imbalance. Low-density lipoprotein cholesterol (LDL) carries cholesterol (a fatty substance) through the blood and delivers it to cells. Excess LDL can cause cholesterol to build up in blood vessels, leading to atherosclerosis. Atherosclerosis is the major cause of blood vessel narrowing, leading to both heart attack and stroke.
Physical inactivity and obesity. Obesity and inactivity are associated with hypertension, diabetes, and heart disease. Waist circumference to hip circumference ratio equal to or above the mid-value for the population increases the risk of ischemic stroke three-fold. (Source:cdc.gov)