The precursors of myocardial infarction include pain in the precordial area, panic and chest tightness, self-perception of weakness and fatigue, and aggravation of angina. 1. Pre-cardiac pain: myocardial infarction often manifests itself as a sudden onset, which is preceded by sudden pressure pain in the retrosternal or precordial area, and may be accompanied by agitation, fear and other emotions. Due to the rapid onset of the disease, taking nitroglycerin tablets usually can not be relieved. 2. Panic and chest tightness: it is often manifested as sudden panic and chest tightness, and the symptoms gradually aggravate, which may be the precursor of myocardial infarction. 3. Feeling of weakness and fatigue: a feeling of weakness and fatigue may appear before myocardial infarction, and it may appear without staying up late at night or being sick, which may be a manifestation of obstruction of blood circulation. 4. Angina aggravation: If the patient himself has a history of angina, and angina aggravation occurs in the recent past, the number of angina episodes increases, and the degree of pain worsens, it may be a precursor of myocardial infarction. If the above symptoms occur, it is recommended to go to a regular hospital and get treatment according to the doctor’s instructions in order to avoid delaying the condition.