What is coronary artery disease (CAD)?
Coronary artery disease is a type of heart disease. The coronary arteries are blood vessels that carry blood and oxygen to the heart muscle (see The Heart & Circulation). They are located along the surface of the heart. When these arteries become clogged with fatty deposits called plaque, it is called coronary artery disease (CAD). Plaque forms in the arteries over many years in a process called atherosclerosis. Clogged arteries can keep the heart from getting enough blood and oxygen and can cause chest pain (angina). If a blood clot forms, it can suddenly cut off blood flow in the artery and cause a heart attack.
Coronary artery disease may also be referred to as coronary heart disease (CHD), ischemic heart disease, or atherosclerotic heart disease.
Atherosclerosis is the buildup of fatty deposits, called plaque, on the inside walls of arteries, the end result of which is coronary artery disease. As plaque builds up in an artery, the artery gradually narrows and can become clogged. The narrower the artery, the less blood that can flow through to provide oxygen to the heart muscle. The artery may also become less elastic, which is called "hardening of the arteries".
Atherosclerosis is the main cause not only of coronary artery disease but of the whole group of diseases called cardiovascular diseases—diseases of the heart and blood vessels. Clogged arteries in the legs or arms lead to peripheral artery disease (PAD), and clogged arteries in the brain can result in stroke.
Plaque is a combination of cholesterol and other fatty materials, calcium, and blood components that stick to the lining of the artery wall. A hard shell or scar covers the plaque. Plaques have various sizes and shapes. Some plaques are unstable and can rupture or burst. When this happens, a blood clot will form inside the artery. If the blood clot totally blocks the artery, it stops blood flow completely. This is what happens in most heart attacks and strokes.
What causes plaque to form in arteries?
Although many risk factors are well known, the exact causes of atherosclerosis are not clear. Too much cholesterol in the blood, damage to the artery wall, and inflammation appear to play important roles in plaque buildup. Researchers are studying why and how the arteries become damaged, how plaque develops and changes over time, and why plaque can break open and lead to blood clots. There may also be other factors that are important in causing atherosclerosis.
What are the symptoms of CAD?
You may not know that you have CAD until you begin to have symptoms from clogged arteries. Chest pain ( angina) and shortness of breath are often the first signs of coronary artery disease. Some people don't know that they have CAD until they have a heart attack.
It is important to know the symptoms of CAD so you can get treatment as early as possible. The earlier you are treated, the better chance you have of living a long and active life. To learn more, visit the Signs & Symptoms section.
Can CAD be prevented?
The best way to prevent heart disease is to have a healthy lifestyle: this means eating a healthy diet, getting regular exercise, and knowing and controlling your heart disease risk factors. Your chances of developing CAD increase with the more risk factors you have.
For a complete list of the factors that affect your risk of developing coronary artery disease, see the risk factors section.
How is CAD diagnosed?
There are many tests used to determine whether or not you have heart disease. Some of these are used to confirm heart disease after you experience symptoms, and some can diagnose it before symptoms appear.
To learn more about tests for heart disease, visit the Tests & Diagnosis section.
How is CAD treated?
There are three main treatments for CAD: medicine, procedures such as angioplasty and stent placement to open blocked arteries, and bypass surgery. None of these treatments cures heart disease, but they can reduce or eliminate the symptoms of heart disease and increase you chances of survival.
In addition to treatments, it is important to make heart-healthy lifestyle changes to slow the progression of heart disease and lower your chances of having a heart attack. Eat a healthy diet, get lots of exercise, and don't smoke.
To learn more about treatments for CAD, visit the Treatment & Recovery section.