Heart attack is short for myocardial infarction, a serious type of coronary heart disease. Myocardial infarction is the death of myocardial cells due to complete occlusion of coronary vessels and the occurrence of sustained longer-term myocardial ischemia. What are the causes of complete occlusion of coronary vessels? There are two main aspects: occlusion of blood vessels due to the presence of severe atheromatous plaques, and occlusion of blood vessels due to the formation of thrombi that are not severe but particularly unstable. 1, severe atherosclerosis The direct cause of heart attack is coronary atherosclerosis, severe lumen narrowing, and the collateral circulation is not fully established, the blood supply is reduced or interrupted, resulting in severe and persistent ischemia of the myocardium and local myocardial ischemic necrosis. 2, vascular plaque instability A dramatic increase in myocardial oxygen consumption can lead to an imbalance in the ratio of blood supply to demand; overwork, excitement, cold, overeating, constipation, alcohol consumption, severe arrhythmia, and a sharp rise in blood pressure can all increase myocardial oxygen demand. Excessive physical work increases the burden on the heart and oxygen consumption; full meals increase blood viscosity; emotional excitement and bowel movements can cause changes in sympathetic vagal tone; cold stimulation leads to coronary spasm. It mostly occurs in atherosclerotic coronary arteries, especially due to certain factors that cause atherosclerotic plaque rupture, platelets gather on the surface of the ruptured plaque, forming thrombus and blocking the lumen; or severe and persistent spasm of coronary arteries, which interrupts blood flow. Therefore, in daily life patients should pay attention to control the plaque progression and increase the stability of plaque to avoid inducing heart attack.