Coronary artery disease (CAD) is the most common form of heart disease and top cause of death in the United States. This condition occurs when the coronary arteries, the blood vessels that supply oxygen-rich blood to your heart muscle, gradually become narrowed or blocked by plaque deposits. The plaque deposits decrease the space through which blood can flow. Poor blood flow can "starve" the heart muscle and lead to chest pain. A heart attack results when blood flow is completely blocked, usually by a blood clot forming over a plaque that has broken open (ruptured).
What causes coronary artery disease?
Coronary artery disease is caused by the buildup of plaque on the inside of your coronary arteries. Plaque is made up of excess cholesterol, calcium, and other substances in your blood that, over time, build up on the inside walls of your coronary arteries and other arteries. This process is called hardening of the arteries, or atherosclerosis. (See an illustration of atherosclerosis) In many people, plaque may begin to form in childhood and gradually develops over a lifetime. Smoking, diabetes, high blood pressure, and high cholesterol all contribute to coronary artery disease.
What are the symptoms?
Since coronary artery disease develops slowly over decades, most people do not know that they have it until the disease is advanced. Typically, the earliest symptoms-chest pain, also called angina, and shortness of breath-occur after age 50.
Unfortunately, sometimes a heart attack is the first sign of coronary artery disease. According to the large, 50-year Framingham Heart Study, 50% of men and 64% of women who died suddenly of coronary artery disease (mostly from heart attack) had no previous symptoms of this disease.
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