Acute myocardial infarction is one of the most serious emergencies in cardiology, and it is very important to identify the symptoms of heart attack. 1.Site and nature: The nature and site of chest pain in heart attack are similar to angina, but more intense and long-lasting. 2.Duration and relief: chest pain lasts more than 20 minutes or even hours to more than 10 hours; rest or nitroglycerin cannot relieve, and activities can aggravate the symptoms of chest pain or chest tightness. 3, attack triggers: excessive physical activity, excessive mood swings, excessive poor lifestyle, excessive climate change, physical disease state. 4.Concomitant symptoms: often accompanied by nausea, vomiting, pale face, cold sweat, dyspnea, panic, low blood pressure, etc. 5. Atypical chest pain: the location of chest pain in heart attack is not behind the sternum in the precordial region, but may be manifested as jaw pain, which patients often easily mistake for dental disease; or manifested as upper abdominal pain, which is often mistaken for gastrointestinal disease; or accompanied by neck pain, left shoulder and left arm pain, which is often mistaken for cervical spondylosis; chest pain does not even occur in diabetic patients or elderly people suffering from heart attack. How to identify atypical chest pain? If the pain site is fixed, the nature of the pain is the same each time, and the triggering cause is the same, atypical angina should be highly suspected. If the duration exceeds 20 minutes doctors, heart attack may occur and it is advisable to seek medical attention as soon as possible. Patients with a history of diabetes must pay attention to atypical chest pain if it occurs.