There are a number of risk factors for stroke.  Some of those risks can be changed through healthy lifestyle decisions, some risk factors cannot be changed, and some risk factors are not very well known.

What Risk Factors Cannot be Changed?

Age 

The chance of having a stroke approximately 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)

Your stroke risk may be greater if a parent, grandparent, sister or brother has had a stroke. Some strokes may be symptoms of genetic disorders like CADASIL (Cerebral Autosomal Dominant Arteriopathy with Sub-cortical Infarcts and Leukoencephalopathy), which is caused by a gene mutation that leads to damage of blood vessel walls in the brain, blocking blood flow. Most individuals with CADASIL have a family history of the disorder — each child of a CADASIL parent has a 50% chance of inheriting the disease. 

Race

Minorities in America, including Hispanics and African Americans, have a much higher risk of death from a stroke than Caucasians do. This is partly because blacks have higher risks of high blood pressure, diabetes and obesity.  Click here for more information on minorities and stroke.

Sex (gender) 

Each year, women have more strokes than men, and stroke kills more women than men. Use of birth control pills, pregnancy, history of preeclampsia/eclampsia or gestational diabetes, oral contraceptive use, and smoking, and post-menopausal hormone therapy may pose special stroke risks for women. Be sure to discuss your specific risks with your doctor.

Prior stroke, TIA or heart attack 

The risk of stroke for someone who has already had one 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’s 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. TIA should be considered a medical emergency and followed up immediately with a healthcare professional. If you’ve had a heart attack, you’re at higher risk of having a stroke, too.

What Risk Factors Can Be Changed, Treated, or Controlled?

High blood pressure

High blood pressure is the leading cause of stroke and the most important controllable risk factor for stroke. Many people believe the effective treatment of high blood pressure is a key reason for the accelerated decline in the death rates for stroke.

Cigarette smoking

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.

Diabetes mellitus 

Diabetes is an independent 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.

Carotid or other artery disease 

The carotid arteries in your neck supply blood to your brain. A carotid artery narrowed by fatty deposits from atherosclerosis (plaque buildups in artery walls) may become blocked by a blood clot. Carotid artery disease is also called carotid artery stenosis.  

Peripheral artery disease 

Peripheral artery disease is the narrowing of blood vessels carrying blood to leg and arm muscles. It’s caused by fatty buildups of plaque in artery walls. People with peripheral artery disease have a higher risk of carotid artery disease, which raises their risk of stroke.

Atrial fibrillation 

This heart rhythm raises the risk for stroke. The heart’s upper chambers quiver instead of beating effectively, 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.

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 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. “Sickled” 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. Also, it appears that low HDL (“good”) cholesterol is a risk factor for stroke in men, but more data are needed to verify its effect in women.

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. Also, a diet containing five or more servings of fruit and vegetables per day may reduce the risk of stroke.

Physical inactivity and obesity 

Being sedentary, obese or both can increase your risk of high blood pressure, high blood cholesterol, diabetes, 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 total of at least 30 minutes of activity on most or all days.

What Risk Factors Are Not Very Well Known?

Geographic location 

Strokes are more common in the southeastern United States than in other areas.  These are the so-called “stroke belt” states.

Socioeconomic factors

There’s some evidence that strokes are more common among low-income people than among more affluent people.

Alcohol abuse 

Alcohol abuse can lead to multiple medical complications, including stroke.  For those who consume alcohol, a recommendation of no more than two drinks per day for men and no more than one drink per day for nonpregnant women best reflects the state of the science for alcohol and stroke risk.

Drug abuse

Drug addiction is often a chronic relapsing disorder associated with a number of societal and health-related problems.  Drugs that are abused, including cocaine, amphetamines and heroin, have been associated with an increased risk of stroke.  Strokes caused by drug abuse are often seen in a younger population.