Myocardial ischemia is not necessarily caused by narrowing of blood vessels, but may also be caused by heart valve disease, anemia, etc. The common cause of myocardial ischemia is coronary heart disease, which occurs on the basis of coronary atherosclerosis with narrowing of arterial vessels. Coronary artery stenosis leads to the occurrence of myocardial ischemia, which manifests as angina pectoris. In addition to coronary heart disease, other diseases can also lead to myocardial ischemia. Heart valve disease is the development of valve lesions, resulting in incomplete closure or stenosis, can also lead to myocardial ischemia, not necessarily the existence of coronary artery stenosis. Patients with anemia can also have insufficient blood supply to the myocardium. Anemia can lead to a decrease in the amount of oxygen in the blood, and the coronary arteries do not show a decrease in blood supply, but the symptoms of myocardial ischemia can occur. Myocardial ischemia patients should pay attention to find the cause of the disease, under the guidance of physicians to clarify the diagnosis, give targeted treatment.