There are many causes of myocardial ischemia, the most common ones are as follows: 1, chronic diseases, such as hypertension, hyperlipidemia and other cerebrovascular diseases, atherosclerosis in the elderly will lead to myocardial ischemia. 2, physical and chemical factors, long-term in a bad environment can easily lead to myocardial ischemia, mostly seen in young people. 3, viral infections, especially EBV infection caused by myocarditis, repeatedly does not heal will also lead to myocardial ischemia. 4. Patients with diabetes mellitus, the slowing down of metabolism in the body will combine with atherosclerosis to cause myocardial ischemia. Myocardial ischemia is affected by many precipitating factors, such as cold weather, emotional excitement, staying up late, obesity, etc. Myocardial ischemia occurs in the case of precipitating factors is more acute and serious, people with a history of myocardial ischemia should avoid precipitating and actively treat the original disease, which can prevent the further development of myocardial ischemia, and usually need regular medical checkups.