A risk factor is something that increases your likelihood of getting a disease or condition.

It is possible to have a stroke without the risk factors listed below. However, the more risk factors you have, the greater your likelihood of having a stroke. If you have a number of risk factors, ask your doctor what you can do to reduce your risk.

Hypertension is the leading risk factor for stroke. Blood pressure is the force of blood on walls of arteries. High blood pressure is when this pressure is higher than expected over a prolonged period of time. Normal blood pressure is in the range of 120/80 mm Hg. Hypertension is defined as blood pressure 140/90 mm Hg. If you have diabetes or chronic kidney disease, it is defined as 130/80 mm Hg.

Hypertension causes turbulent blood flow that can damage blood vessels walls and overtime causes them to weaken. If you have hypertension and are not keeping your blood pressure in a specific target range, you have an increased risk of having a stroke. Hypertension has no symptoms, so it is important to have your blood pressure checked regularly.

Other risk factors can also be modified through lifestyle changes while other can not be reduced but are important to know:

Smoking is a major contributing factor to stroke. Smoking can:

  • Irritates and narrows blood vessels which can narrow blood vessel and decrease blood flow
  • Contributes to the build up of arterial plaque
  • Raises heart rate and blood pressure which can place extra pressure on weakened blood vessel walls

As a result, cigarette smokers are 2-4 times as likely as nonsmokers to have a stroke than nonsmokers.

Nonsmokers who are exposed to smoking are at risk as well.

A diet that is high in trans fat, saturated fat, and low in fruits, vegetables, whole grains, and fiber increases your risk of having a stroke. Poor diet contributes to to high cholesterol, obesity, and glucose intolerance disorders such as metabolic syndrome and diabetes, which are all independent risk factors for stroke.

Physical inactivity doubles your risk for a heart attack or stroke. Regular moderate to intense exercise improves heart function and promotes healthy arteries. It also helps reduce the chance of other stroke risk factors such as hypertension, high cholesterol, and diabetes.

Talk to your doctor before you start any exercise program and gradually increase your intensity.

Drinking too much alcohol can increase blood pressure, blood triglycerides that contribute to plaque build up, and increase the risk of abnormal heart rhythms (arrhythmias). Drinking too much alcohol can increase blood pressure and lead to other cardiovascular problems.

There is some evidence supporting that moderate drinking lowers your risk of cardiovascular disease. Moderate means an average of one drink per day for women or two drinks per day for men.

It is important to remember, however, that moderate ingestion of alcohol can affect your overall health. Based on currently available data, taking up regular consumption of alcohol is not encouraged for people who do not drink or drink sporadically.

Illicit drug use, especially cocaine, can cause blood vessel damage, which can lead to blood clots and arterial spasms. Strokes are more likely in people with vascular damage. Drug users also have an increased risk of dying from sudden cardiac arrest .

There are risk factors that are unique to women. They may be influenced by conditions and/or treatments. In some cases, it may lead to an increased risk of blood vessel damage or blood clots that can interfere with blood flow to the brain, leading to a stroke. These include:

Risk of stroke dramatically increases in combination with other risk factors you may have, especially smoking.

Cardiovascular diseases are major contributors to stroke. Many chronic conditions, such as coronary artery disease or atrial fibrillation, affect heart function, making it difficult to meet the body's demands. Long-term problems cause damage to blood vessels, increasing the risk of blockage (ischemic stroke) or bleeding (hemorrhagic stroke).

Some cardiovascular issues include:

  • Transient ischemic attacks (TIA)—Sometimes referred to as mini-strokes, TIAs occur when a blood flow is temporarily reduced by narrowing or blockage of blood vessels that supply the brain. The situation usually corrects itself within 24 hours. TIAs are serious and often serve as a warning for a future major stroke.
  • Brain aneurysm —An outpouching of a blood vessel wall in the brain that form in areas where the artery wall is weak or thin. The bulging, blood-filled pocket can put pressure on parts of the brain, or in some cases, burst.
  • Ateriovenous malformations (AVM)—A rare condition marked by abnormal connections that occur between arteries and veins. Instead of an artery supplying an area of the brain with blood, it is connected directly to a vein that takes it away, bypassing the brain tissue that needs it.
  • Vasculitis —Inflammation of the blood vessels. Inflammation over time may damage blood vessels, which in turn may bleed or burst.
  • Silent stroke —Brain tissue damage found incidentally during imaging tests may indicate areas where previous strokes occurred. Silent strokes can be a warning for future stroke.
  • Previous heart attack or stroke

Vascular dementia is a type of dementia that is caused by problems with blood supply to the brain. These deficits may be caused by multiple TIAs. Both conditions are signs of increased risk of having a major stroke.

Having certain psychological disorders, such as depression, panic disorder, anxiety, or prolonged emotional or occupational stress are associated with an increased risk of stroke. Some disorders and treatments may lead to poor lifestyle choices, such as smoking, weight gain, or lack of physical exercise.

Obstructive sleep apnea (OSA) is a disorder characterized by repeated episodes of complete or partial airway obstruction during sleep. The disorder is associated with disrupted sleep patterns and decreased oxygen saturation (the amount of oxygen carried in the bloodstream). OSA has been linked to several disorders, including cardiovascular disease and early death. OSA is also an independent risk factor for hypertension, heart failure, diabetes, and heart attack.

Brain function normally decreases as we age. This decrease is generally not enough to cause problems, but can increase the risk of developing cardiovascular disease, which can lead to a stroke. Some changes include stiffer blood vessels, small breaks in blood vessels, and minor cognitive and memory loss.

The risk of stroke increases as you age. Although men are more likely to have a stroke at a younger age, women overall tend to have more strokes and die from them. This may be due to risk factors that are unique to women in combination with standard ones.

Having family members that have had a stroke or history of cardiovascular disease increases your risk as well. You are also at a higher risk if you have certain genetic abnormalities. For example, your blood may have a tendency to clot, which can increase the risk of narrowed or blocked arteries.

In general, African Americans have a higher incidence of hypertension than Caucasians and, therefore, a higher risk of having a stroke. Stroke risk is also higher among American Indians and Native Alaskans.