Myocardial ischemia will occur when staying up late: First, when staying up late, the patient will have an obvious increase in sympathetic tone, at this time there will be increased myocardial contraction, accelerated heartbeat, insufficient blood supply to the heart, there will also be an increase in cardiac conduction velocity, which will trigger ischemia, stenosis and spasm of the coronary arteries, and there will be insufficient blood supply and oxygen supply to the cardiac muscle cells. Therefore, there will be myocardial ischemia, and patients will have obvious chest tightness, shortness of breath, palpitations, and anterior heart discomfort along with weakness of the body. Second, for patients with a clear past history of hypertension, patients will also experience an increase in blood pressure when staying up late. This will increase the anterior and posterior load on the heart, and therefore will further lead to the generation of myocardial ischemia. Third, staying up late can also lead to dysregulation of the body’s neurohumoral endocrine system, which can also lead to an increase in myocardial ischemia.