Heart disease is
caused by narrowing of the coronary arteries that feed the heart. Like any
muscle, the heart needs a constant supply of oxygen and nutrients, which are
carried to it by the blood in the coronary arteries. When the coronary
arteries become narrowed or clogged by cholesterol and fat deposits--a
process called atherosclerosis--and cannot supply enough blood to the heart,
the result is coronary heart disease (CHD). If not enough oxygen-carrying
blood reaches the heart, you may experience chest pain called angina. If the
blood supply to a portion of the heart is completely cut off by total
blockage of a coronary artery, the result is a heart attack. This is usually
due to a sudden closure from a blood clot forming on top of a previous
narrowing. Cholesterol is a
waxy, fat-like substance that occurs naturally in all parts of the body and
that your body needs to function normally. It is present in cell walls or
membranes everywhere in the body, including the brain, nerves, muscle, skin,
liver, intestines, and heart. Your body uses cholesterol to produce many
hormones, vitamin D, and the bile acids that help to digest fat. It takes
only a small amount of cholesterol in the blood to meet these needs. If you
have too much cholesterol in your bloodstream, the excess is deposited in
arteries, including the coronary arteries, where it contributes to the
narrowing and blockages that cause the signs and symptoms of heart disease.
For more information, visit this article at the National Heart, Lung, and Blood Institute.