Myocardial infarction often has severe symptoms, such as profuse sweating, severe chest tightness, chest pain, and most will have ST-segment elevation by ECG, and blood tests for cardiac enzymes will have a significant increase in the cardiac triad. The diagnosis of myocardial infarction requires a combination of symptoms, ECG and blood tests. Symptoms of myocardial infarction tend to be more intense and may include severe chest tightness, chest pain, panic, sweating, and in atypical cases, severe abdominal pain. Symptoms continue unrelieved, and nitroglycerin is ineffective when taken with nitroglycerin. Patients with myocardial infarction have blood drawn for three cardiac tests: creatine kinase, creatine kinase isoenzyme, and troponin, and the indicators may be positive. Electrocardiogram is also indispensable, most of the acute myocardial infarction appears ST segment elevation, non-ST segment elevation myocardial infarction will have ST segment depression, T wave inversion. The dynamic evolution detected by ECG comparison can indicate myocardial infarction. If the presence of myocardial infarction is suspected, it is recommended to go immediately to the hospital emergency or cardiology department.