What causes a heart attack?
Heart attacks and angina are both outcomes of coronary heart disease. There is no single cause for coronary heart disease, but there are risk factors that increase your chance of getting it. The more risk factors you have, the more likely you are to have a heart attack.
A heart attack occurs when one or more of your coronary arteries become blocked. Over time, a coronary artery can narrow from the buildup of various substances, including cholesterol (atherosclerosis). This condition, known as coronary artery disease, causes most heart attacks.
During a heart attack, one of these plaques can rupture and spill cholesterol and other substances into the bloodstream. A blood clot forms at the site of the rupture. If large enough, the clot can block the flow of blood through the coronary artery, starving the heart muscle of oxygen and nutrients (ischemia).
You might have a complete blockage or partial. A complete blockage means you've had an ST elevation myocardial infarction (STEMI). A partial blockage means you've had a non-ST elevation myocardial infarction (NSTEMI). Diagnostic steps and treatment might be different depending on which you've had.
Another cause of a heart attack is a spasm of a coronary artery that shuts down blood flow to part of the heart muscle.