Coronary artery disease (CAD) happens when the arteries feeding the heart muscle become narrowed by the build up of plaque (fatty material) on the inner walls. This build up reduces blood-flow to the heart muscle, decreasing the oxygen available to the muscle.
The build up may not cause trouble when it starts, but as time goes on and the plaque builds up, you may experience pain (pressure, squeezing, heaviness, tightness, difficulty breathing). This pain is referred to as angina
. It may be felt in the chest, back, arms, neck or jaw. Angina is usually relieved with rest and/or medication.
Angina does not cause permanent damage to the heart muscle. When a clot forms or a long spasm occurs in the narrowed artery, a heart attack may result. This cuts off all blood flow and oxygen to the area of muscle that is beyond the blockage. With a heart attack, you may feel a crushing pain in the center of your chest that radiates (moves) to your neck, jaw, shoulders, arms, or back.
You may also notice weakness, nausea, shortness of breath, and/or sweating. Once in a while a heart attack occurs with no pain at all ( a "silent" heart attack).
A heart attack requires urgent and immediate medical care to reduce or eliminate the possibility of permanent heart damage.