Atherosclerosis

What is atherosclerosis?

Atherosclerosis, also called “hardening of the arteries,” occurs when fatty substances build up in the artery wall. The main fatty substance in this buildup is cholesterol. This buildup makes the artery stiffer than normal and causes partial or complete blockage of the flow of blood and oxygen to the body.

Atherosclerosis affects mainly the medium-sized arteries such as the coronary (heart) arteries, carotid (neck) arteries, cerebral (brain) arteries, and kidney arteries. It is also often found in the aorta, which is the largest artery in the body, and the branches of the aorta to the arms and legs. Atherosclerosis tends to build up near branching points in the arteries.

Atherosclerosis is more common as people get older and gets worse over time. It is the leading cause of death and disability in the United States.

How does it occur?

Atherosclerosis develops in a sequence of events. The first event is thought to be an injury that damages the inner lining of an artery. The injury may be caused by high blood pressure in the artery. Other causes may be damage by a virus, irritants such as nicotine or drugs, or an allergic reaction.

White blood cells called monocytes move into the injured wall of the artery. The monocytes change into cells called macrophages, which start to gobble up lipids. Lipids, which include fats and cholesterol, are carried all over the body by the blood. The macrophages gobble up so much that they burst, causing more injury and repeating the cycle.

Platelets, another component of blood, also recognize the injury and attach themselves to the injured area. The platelets try to repair the injured artery by making more muscle cells grow in the wall of the artery. This thickens and stiffens the artery wall. The amount of fibrous or connective tissue in the injured area increases. The entire thickened area is then called a plaque. The plaque may slowly get larger or it may rupture.

Some plaques grow very slowly and the artery gradually becomes more narrow. In time, this narrowing may block the artery enough to reduce the blood flow through it. When that happens, the part of the body beyond the narrowing begins to suffer from lack of oxygen.

When the surface of a plaque ruptures (breaks open), a clot forms at the rupture. The clot may get large enough to partially or completely block the flow of blood through the artery. No one knows what causes plaques to rupture. A heart attack, stroke, or kidney failure can result.

What are the symptoms?

Atherosclerosis can go on unnoticed for many years until a serious lack of blood flow to a part of the body causes symptoms. The symptoms may be constant or they may come and go. They may include problems such as:

Pain in the calf muscles when you exercise (intermittent claudication)
Pain in the chest (angina)
Dizziness
A mini-stroke (transient ischemic attack, or TIA)

How is it diagnosed?

Your health care provider will ask about your symptoms and examine you. You may have one or more of these tests:

Angiogram, which uses special x-rays to outline the arteries
Ultrasound (sonogram), which uses sound waves to make pictures of your arteries
Electrocardiogram (ECG), which records electrical impulses of your heart
Doppler ultrasound, which can measure both the amount of blockage and the speed of blood flow in your arteries.

How is it treated?

Depending on your symptoms, your health care provider may prescribe medicine to reduce blood clotting or to relax the blood vessels. You may need surgery. Your provider may also treat conditions related to the atherosclerosis such as kidney damage or coronary artery disease.

Your health care provider may advise major lifestyle changes to try to halt or reverse the buildup of plaque in your arteries. These lifestyle changes are described below as ways to take care of yourself.

How can I take care of myself?

Take the medicine prescribed and follow your health care provider’s advice for lifestyle changes.
Have your blood pressure and blood cholesterol checked regularly.
If you smoke, quit. Tell your provider if you need help quitting.
If you are overweight, talk to your provider about losing weight.
Exercise regularly under the guidance of your provider.
Switch to a low-fat, low-cholesterol, high-fiber diet. Your provider or a dietician can tell you which foods to avoid.
Find ways to reduce stress.
If your provider approves, take an aspirin a day. However, check with your provider first. There may be reasons why you should not take aspirin. Your provider may prescribe other medicines that can slow the progress of atherosclerosis.

How can I help prevent atherosclerosis?

Because the cause of atherosclerosis is unknown, it cannot be prevented. However, the lifestyle changes described above can slow its progress.

Information obtained from GE Medical Systems; authorization given to reproduce on HCNW web site 9/02.
Developed by Donald L. Warkentin, MD, and Ann Carter, MD, for McKesson Clinical Reference Systems.
Published by McKesson Clinical Reference Systems.
Copyright © 1997-2002 McKesson Health Solutions LLC. All rights reserved.
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.