Myocardial infarction is like an “earthquake” in the heart that occurs suddenly, often unannounced, and causes serious health problems. Although current technology does not yet have a test or warning sign to accurately predict that a person will have a myocardial infarction at a particular time, most myocardial infarctions do occur with some precursors that are often overlooked. These precursors may be subtle, slow in onset, mild in pain or discomfort, and sometimes the patient may not be able to identify the discomfort on their own, so they are not alerted and seek prompt medical attention. Some of the manifestations described below may indicate that a myocardial infarction is about to strike and are worth noting: 1. chest discomfort: most myocardial infarction attacks are preceded by a discomfort that lasts for several minutes behind the sternum, which disappears and then recurs, and is manifested by symptoms such as chest pressure, chest tightness, breath-holding, tightness, or pain. 2, discomfort in other parts of the body: including pain, acidity, tightness, pressure, seizure and other sensations in one or both arms, back, neck, jaw, tongue root, stomach and other parts. 3, shortness of breath: shortness of breath symptoms may or may not be accompanied by chest discomfort. 4.Other manifestations: cold sweat, nausea, dizziness. The symptoms of myocardial infarction in the vast majority of people are chest pain and chest tightness and breath-holding. Compared to men, women show more shortness of breath, nausea and vomiting, back pain or jaw pain than men. Some people may simply feel tired. Some older diabetics may not feel anything due to nerve damage, and even myocardial infarction is painless. Knowing this knowledge can buy time for early response and rescue, because for myocardial infarction patients “time is heart muscle, time is life”.