Myocardial ischemia is caused by narrowing of the coronary arteries and insufficient blood and oxygen supply to the heart muscle, and early symptoms vary from person to person. In some patients, due to insensitivity or low activity, ischemia is usually not induced at rest and may not have any symptoms, which are often detected during electrocardiogram and cardiac ultrasound examinations. Patients with symptoms may present early with exertion-related chest tightness, chest pain, weakness, and decreased activity endurance, due to early ischemia that is not obvious and only appears when the patient is exercising heavily or when myocardial oxygen consumption increases. The symptoms are usually dullness and tightness in the precordial region, and a few may have burning pain, which usually lasts for several minutes to more than 10 minutes and may be relieved by rest or nitroglycerin. Some patients may experience dizziness, nausea, toothache, cervical pain, etc. Once these symptoms appear, medical treatment should be sought promptly to avoid inducing myocardial infarction. In addition to the application of nitrates, antiplatelet and lipid-lowering drugs should be combined with the treatment. Patients must take more rest during the treatment period to avoid staying up late, straining and getting cold.