A risk factor is a condition or behavior that increases your chances of getting a disease. 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 increase. These risk factors for stroke cannot be changed by medical treatment or lifestyle changes. - Age. Although stroke risk increases with age, stroke can occur at any age. Recent studies have found that stroke rates among people under 55 grew from 13 percent in 1993-1994, to 19 percent in 2005. Experts speculate the increase may be due to a rise in risk factors such as diabetes, obesity, and high cholesterol. Age. Although stroke risk increases with age, stroke can occur at any age. Recent studies have found that stroke rates among people under 55 grew from 13 percent in 1993-1994, to 19 percent in 2005. Experts speculate the increase may be due to a rise in risk factors such as diabetes, obesity, and high cholesterol. - Gender.  Men have a higher risk for stroke, but more women die from stroke. Gender.  Men have a higher risk for stroke, but more women die from stroke. - 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 U.S. Studies show that the age-adjusted incidence of stroke is about twice as high in African Americans and Hispanic Americans as in Caucasians. An important risk factor for African Americans is sickle cell disease, which can cause a narrowing of arteries and disrupt blood flow. 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 U.S. Studies show that the age-adjusted incidence of stroke is about twice as high in African Americans and Hispanic Americans as in Caucasians. An important risk factor for African Americans is sickle cell disease, which can cause a narrowing of arteries and disrupt blood flow. - 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 could also contribute to familial stroke. 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 could also contribute to familial stroke. Some of the most important risk factors for stroke that CAN be treated are - high blood pressure  - smoking  - heart disease  -  high blood cholesterol  - warning signs or history of a stroke  - diabetes. high blood pressure smoking heart disease high blood cholesterol warning signs or history of a stroke diabetes. High Blood Pressure High blood pressure, also called hypertension, is by far the most potent risk factor for stroke. 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. Here are some ways to reduce blood pressure: - Maintain proper weight.  - Avoid drugs known to raise blood pressure.  - Cut down on salt.  - Eat fruits and vegetables to increase potassium in your diet.  - Exercise more. Maintain proper weight. Avoid drugs known to raise blood pressure. Cut down on salt. Eat fruits and vegetables to increase potassium in your diet. Exercise more. Your doctor may prescribe medicines that help lower blood pressure. Controlling blood pressure will also help you avoid heart disease, diabetes, and kidney failure. Smoking Cigarette smoking has been linked to the buildup of fatty substances 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. Also, nicotine raises blood pressure, carbon monoxide reduces the amount of oxygen your blood can carry to the brain, and cigarette smoke makes your blood thicker and more likely to clot. Your doctor can recommend programs and medications that may help you quit smoking. By quitting -- at any age -- you also reduce your risk of lung disease, heart disease, and a number of cancers including lung cancer. Heart Disease Heart disease, including common heart disorders such as coronary artery disease, valve defects, irregular heart beat, 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. The most common blood vessel disease, caused by the buildup of fatty deposits in the arteries, is called atherosclerosis, also known as hardening of the arteries. Your doctor will treat your heart disease and may also prescribe medication, such as aspirin, to help prevent the formation of clots. Your doctor may recommend surgery to clean out a clogged neck artery if you match a particular risk profile. High Blood Cholesterol A high level of total cholesterol in the blood is a major risk factor for heart disease, which raises your risk of stroke. Your doctor may recommend changes in your diet or medicines to lower your cholesterol. Warning Signs or History of Stroke Experiencing warning signs and having a history of stroke are also risk factors for stroke. Transient ischemic attacks, or TIAs, are brief episodes of stroke warning signs that may last only a few moments and then go away. If you experience a TIA, get help at once. Call 911. 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 drawing on body systems that now do double duty. That means a second stroke can be twice as bad. Diabetes Having diabetes is another risk factor for stroke. 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. Also, if blood glucose levels are high at the time of a stroke, then brain damage is usually more severe and extensive than when blood glucose is well-controlled. Treating diabetes can delay the onset of complications that increase the risk of stroke.