Stroke Explained : Part 2

by CDC

(Page 2 of 3)

Heart Disease

Common heart disorders such as coronary artery disease can also increase a person's risk for stroke. Coronary artery disease (CAD) occurs when the arteries that supply blood to the heart muscle become hardened and narrowed due to the buildup of plaque. Plaque (a mixture of fatty substances, including cholesterol and other lipids) and blood clots can build up inside the artery walls, causing thickening, hardening, and loss of elasticity. They can result in decreased or blocked blood flow and lead to a heart attack. Also, heart problems such as valve defects, irregular heart beat, and enlargement of one of the heart's chambers can result in blood clots that may break loose and cause a stroke. Persons with heart disease may be given medicines such as aspirin to help prevent clots from forming.

Atrial Fibrillation

A heart condition known as atrial fibrillation is a major concern. Atrial fibrillation is irregular beating of the upper chambers, or atria, of the heart. When the atria quivers instead of beating in a regular pattern, blood is not fully pumped out of them and may pool and clot. The clots can then leave the heart and travel to the brain, causing a stroke. Atrial fibrillation affects as many as 2.2 million Americans. About 15 percent of stroke patients have had atrial fibrillation before they experience a stroke.

Diabetes

Diabetes is another disease that increases a person's risk for stroke. With diabetes, the body does not make enough insulin, cannot use its own insulin as well as it should, or both. This causes sugars to be unavailable to the body tissues and to build up in the blood. People with diabetes have 2 to 4 times the risk of stroke compared to people without diabetes. Further, having diabetes can worsen the outcome of stroke.

Tobacco Use

Smoking almost doubles a person's risk for ischemic stroke, independently of other risk factors. Cigarette smoking increases the risk of stroke by promoting atherosclerosis and increasing the levels of blood clotting factors, such as fibrinogen. Also, nicotine raises blood pressure, and carbon monoxide reduces the amount of oxygen that blood can carry to the brain.

Other Factors

Blood Cholesterol Levels

Some strokes can be caused by a narrowing of the arteries through the buildup of plaque, a mixture of fatty substances, including cholesterol and other lipids. This is called atherosclerosis. Plaque and blood clots build up inside the artery walls, causing thickening, hardening, and loss of elasticity. These can lead to decreased blood flow and to stroke if they occur in the arteries to the brain.

Cholesterol is a waxy substance produced by the liver. It is needed by the body, and the liver makes enough cholesterol for the body's needs. Excess cholesterol-usually from eating foods that contain high levels of cholesterol and saturated fats-contributes to atherosclerosis.

There are two major kinds of cholesterol, one that is good, and one that is bad when there is too much of it. A higher level of high-density lipoprotein cholesterol, or HDL, is considered good. However, higher levels of low-density lipoprotein, or LDL, can lead to atherosclerosis and stroke. A lipoprotein profile can be done to measure several different kinds of cholesterol as well as triglycerides (another kind of fat found in the blood).

Alcohol

Generally, excessive alcohol use can lead to an increase in blood pressure, which increases the risk for stroke.

Genetic Risk Factors

Stroke can run in families. Genes play a role in stroke risk factors such as high blood pressure, heart disease, diabetes, and vascular conditions. It is also possible that an increased risk for stroke within a family is due to factors such as a common sedentary lifestyle or poor eating habits, rather than hereditary factors.

About the Author

www.cdc.gov
The Centers for Disease Control and Prevention (CDC) is one of the 13 major operating components of the Department of Health and Human Services (HHS), which is the principal agency in the United States government for protecting the health and safety of all Americans and for providing essential human services, especially for those people who are least able to help themselves.