Cause
Coronary artery disease is caused by the buildup of
plaque on the inside of your
coronary
arteries
. In most people, plaque buildup begins early in life and
gradually develops over a lifetime.1
Coronary artery disease (CAD) typically begins when the inside
walls of the coronary arteries are damaged, due to one or more underlying
conditions, such as:
Plaque, which is made up of excess cholesterol, calcium, and other
substances in your blood, builds up on the damaged inner walls of your coronary
arteries. This process usually occurs throughout the body and is called
atherosclerosis, or "hardening of the arteries." (See
a picture of
atherosclerosis
.)
Over time, plaque buildup narrows the coronary arteries and can
lead to
ischemia (insufficient blood flow to the heart
muscle). Ischemia can weaken the heart muscle, but it usually does not cause
heart muscle cells to die.
However, heart muscle cells can die if blood flow is severely
reduced or completely blocked for a period of time. This is called myocardial
infarction, or
heart attack.