Mostly, heart attacks happen due to coronary artery disease; it is the buildup of plaque on the inner walls of the coronary arteries. Hardened plaque can break open, and attracts blood clot to form at the surface. A heart attack occurs if the blood clot is large enough to block most or cut off all the blood supply to the artery.
Heart Attack Causes
Due to blockage oxygen, rich blood cannot reach some parts of the heart muscle fed by the artery. Inadequate oxygen supply damages the heart muscle. If the blockage is not clear quickly, the damaged heart muscle starts to die.
Heart attack may also happen due to problems with the microscopic blood vessels of the heart called micro-vascular disease. It is more common in women than in men.
Fewer common causes of heart attack are a sudden contraction (spasm – tightening) of the coronary artery, that blocks blood flow through the artery. This contraction can occur in coronary artery that has or does not have coronary heart disease. It is still unknown what causes this coronary artery contraction, but mostly common cause may be:
- When taking cocaine
- Cigarette smoking
- Mental stress or pain
- Exposing to cold temperatures