What Is Atherosclerosis?

Atherosclerosis (ath-er-o-skler-O-sis) is a disease in which plaque (plak) builds up inside your arteries. Arteries are blood vessels that carry oxygen-rich blood to your heart and other parts of your body.

Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. Over time, plaque hardens and narrows your arteries, limiting the flow of oxygen-rich blood to your organs and other parts of your body. This can lead to serious problems, including heart attack,stroke, or even death.

Atherosclerosis

Figure A shows a normal artery with normal blood flow. Figure B shows an artery with plaque buildup.

Figure A shows a normal artery with normal blood flow. Figure B shows an artery with plaque buildup.

Atherosclerosis-Related Diseases

Atherosclerosis can affect any artery in the body, including arteries in the heart, brain, arms, legs, and pelvis. As a result, different diseases may develop based on which arteries are affected.

Coronary Heart Disease

Coronary heart disease (CHD) occurs if plaque builds up in the coronary arteries. These arteries supply oxygen-rich blood to your heart.

Plaque narrows the coronary arteries and reduces blood flow to your heart muscle. It also makes it more likely that blood clots will form in your arteries. Blood clots can partially or completely block blood flow.

When blood flow to your heart muscle is reduced or blocked, it can lead to angina (chest pain) and a heart attack. CHD also is called coronary artery disease or heart disease. It's the leading cause of death for both men and women in the United States.

Plaque also can form in the heart's smallest arteries. When this happens, it's called coronary microvascular disease (MVD). In coronary MVD, plaque doesn't always cause blockages in the arteries as it does in CHD.

Carotid Artery Disease

Carotid (ka-ROT-id) artery disease occurs if plaque builds up in the arteries on each side of your neck. These arteries supply oxygen-rich blood to your brain. When blood flow to your brain is reduced or blocked, it can lead to a stroke.

Peripheral Arterial Disease

Peripheral arterial disease (P.A.D.) occurs if plaque builds up in the major arteries that supply oxygen-rich blood to your legs, arms, and pelvis.

When blood flow to these parts of your body is reduced or blocked, it can lead to numbness, pain, and, sometimes, dangerous infections.

Overview

The cause of atherosclerosis isn't known. However, certain traits, conditions, or habits may raise your risk for the disease. These conditions are known as risk factors.

You can control some risk factors, such as lack of physical activity, smoking, and an unhealthy diet. Others you can't control, such as age and a family history of heart disease.

Some people who have atherosclerosis have no signs or symptoms. They may not be diagnosed until after a heart attack or stroke.

The main treatment for atherosclerosis is lifestyle changes. You also may need medicines and medical procedures. These treatments, along with ongoing medical care, can help you live a healthier life.

Outlook

Better treatments have reduced the number of deaths from atherosclerosis-related diseases. These treatments also have improved the quality of life for people who have these diseases. However, atherosclerosis remains a common health problem.

You may be able to prevent or delay atherosclerosis and the diseases it can cause. Making lifestyle changes and getting ongoing care can help you avoid the problems of atherosclerosis and live a long, healthy life.

Revised December 2009
National Heart Lung and Blood Institute 

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