Evaluating the risk for stroke is based on heredity, natural
processes, and lifestyle. Many risk factors for stroke can be changed or
managed, while others that relate to hereditary or natural processes
cannot be changed.
What risk factors for stroke can’t be changed?
- Age - The chance of having a stroke more than doubles for
each decade of life after age 55. While stroke is common among the
elderly, a lot of people under 65 also have strokes.
- Heredity (family history) and race - Your stroke risk is
greater if a parent, grandparent, sister or brother has had a stroke.
African-Americans have a much higher risk of death from a stroke than
Caucasians. This is partly due to higher rates of high blood pressure
and diabetes in this group.
- Sex (gender) – Stroke is more common in men than in
women. In most age groups, more men than women will have a stroke in a
given year. However, more than half of total stroke deaths occur in
women. At all ages, more women than men die of stroke. Use of birth
control pills and pregnancy pose special stroke risks for women.
- Prior stroke, Transient Ischemic Attack (TIA) or heart attack
– The risk for someone who has already had one stroke is many times
that of a person who has not. Transient ischemic attacks (TIAs) are
“warning strokes” that produce stroke-like symptoms but no lasting
damage. TIAs are strong predictors of stroke. A person who had one or
more TIAs is almost 10 times more likely to have a stroke than someone
of the same age and sex who hasn’t. Recognizing and treating TIAs can
reduce your risk of a major stroke. If you’ve had a heart attack, you’re
at higher risk of having a stroke, too.
What stroke factors can be changed, treated or controlled?
- High blood pressure – High blood pressure or hypertension
is the number one cause of stroke. High blood pressure can damage the
small blood vessels of the brain. High blood pressure is the most
important controllable risk factor for stroke. Many people believe the
effective treatment of blood pressure is a key reason for the
accelerated decline in death rates for stroke.
- Cigarette smoking – Tobacco use in any form, especially
cigarette smoking, is very bad for your health. In recent years, studies
have shown cigarette smoking to be an important risk factor for stroke.
The nicotine and carbon monoxide in cigarette smoke damage the
cardiovascular system in many ways. The use of oral contraceptives
combined with cigarette smoking greatly increases stroke risk in women.
- Diabetes mellitus –
Diabetes is a risk factor for stroke. Many people with diabetes also
have high blood pressure, high blood cholesterol and are overweight.
This increases their risk even more. While diabetes is treatable, the
presence of the disease still increases your risk of stroke. Diabetes
causes disease of small blood vessels in the brain and can lead to a
- Carotid or other artery disease – The carotid arteries in
your neck supply blood to your brain. A carotid artery narrowed by
fatty deposits from plaque build up in the artery walls
(atherosclerosis) may become blocked by a blood clot. Carotid artery
disease is also called carotid artery stenosis. Peripheral artery
disease is narrowing of blood vessels carrying blood to legs and arm
muscles. It’s caused by fatty build-ups of plaque in artery walls.
People with peripheral artery disease have a high risk of carotid artery
disease, which raises their risk of stroke. Causes of carotid artery
disease are high blood pressure, diabetes, a diet high in fat, high
cholesterol and smoking.
- Atrial fibrillation – This heart rhythm disorder raises
the risk for stroke. The heart’s upper chambers quiver instead of
beating regularly, which can let the blood pool and clot. If a clot
breaks off, enters the bloodstream and lodges in an artery leading to
the brain, a stroke results. Click here to watch Dr. Anthony Dorsey explain more about irregular heartbeat conditions.
- Other heart disease – People with coronary heart disease
or heart failure have a higher risk of stroke than those with hearts
that work normally. Dilated cardiomyopathy (an enlarged heart), heart
valve disease and some other types of congenital heart defects also
raise the risk of stroke.
- Sickle cell disease (also called sickle cell anemia) –
This is a genetic disorder that mainly affects African-American and
Hispanic children. “Sickle-shaped” red blood cells are less able to
carry oxygen to the body’s tissues and organs. These cells also tend to
stick to blood vessel walls, which can block arteries to the brain and
cause a stroke.
- High blood cholesterol – People with high blood
cholesterol have an increased risk for stroke. High blood cholesterol
can be reduced by eating right (avoid fried, fatty foods) and exercising
routinely. It may also require medication.
- Poor diet – Diets high in saturated fat, trans fat and
cholesterol can raise blood cholesterol levels. Diets high in sodium
(salt) can contribute to increased blood pressure. Diets with excess
calories can contribute to obesity. A diet containing five or more
servings of fruit and vegetables per day may reduce the risk of stroke.
- Physical inactivity and obesity – Being inactive, obese
or both can increase your risk of high blood pressure, high blood
cholesterol, diabetes and heart disease and stroke. So go on a brisk
walk, take the stairs, and do whatever you can to make your life more
active. Try to get a least 30 minutes of moderate physical activity five
days of the week, or 20 minutes of vigorous physical activity, three
days a week, with your doctor’s approval.
- History of Transient Ischemic Attacks (TIAs) – A person
who has had one (or more) TIAs is almost 10 times more likely to have a
stroke than someone of the same age and sex who has not had a TIA.
- Excessive Alcohol Use – More than two drinks per day raises blood pressure, and binge drinking can lead to stroke.
- Drug Abuse (certain kinds) – Intravenous drug abuse
carries a high risk of stroke from cerebral embolisms (blood clots).
Cocaine use has been closely related to strokes, heart attacks and a
variety of other cardiovascular complications. Some of them, even among
first-time cocaine users, have been fatal.
Other risk factors of stroke to consider:
- Where a Person Lives – Strokes are more common among
people living in the southeastern United States than in other areas.
This may be due to regional differences in lifestyle, race, cigarette
smoking and diet.
- Temperature, Season, and Climate – Stroke deaths occur more often during periods of extreme temperatures.
- Socioeconomic Factors – There is some evidence that strokes are more common among low-income people than among more affluent people.
High folic acid intake may reduce the risk of strokes:
A recent study, which included two decades of following nearly 10,000
American adults, found that people with daily diets that included at
least 300 micrograms of folic acid, a B vitamin, cut their risk of
stroke by 20 percent, compared with people who ate less than 136
micrograms of folic acid a day. The reduced risk of stroke was
associated with higher intake of folic acid among both men and women,
regardless of physical activity levels and smoking habits.
Some studies have demonstrated that folic acid lowers levels of
homocysteine in the blood. Homocysteine is an amino acid that has been
linked to a higher risk of atherosclerosis (hardening of the arteries
that can lead to stroke and heart attack).
Foods that contain folic acid include:
- citrus fruits
- leafy vegetables
- grain products
Wheat flour has been fortified with folic acid since 1998, by order
of the US Food and Drug Administration (FDA), to reduce the increased
risk of birth defects associated with low-folic acid diets. Always
consult your physician for more information.