As the incidence of coronary heart disease is increasing year by year and the trend of coronary heart disease is getting younger, it is now advocated to see a doctor if you have chest pain, and some hospitals have set up chest pain clinics specifically to screen for coronary heart disease. However, it should be noted that not all chest pains are angina or heart-related, and many people without heart disease also have anterior chest discomfort, which disappears instantly or is persistent and vague (such as lasting for several hours, or even a day, several days, etc.), and has nothing to do with activities, and even activities also make chest pain relief, and often occurs after the disappearance of the triggering factors, such as during the day when more activities do not have any obvious discomfort, but at night when resting This pain is often unrelated to the heart and may be related to nerve or muscle strain, or may be caused by neurosis (also called cardiac neurosis). In addition, pneumonia, intercostal neuritis, costochondritis, gastritis, esophagitis and herpes zoster can also cause discomfort such as chest pain. The diagnosis is usually made on the basis of the typical features and signs of angina pectoris, relief with nitroglycerin, age and the presence of coronary heart disease predisposing factors, except for other causes of angina pectoris. In China, many patients often have atypical manifestations of angina pectoris attacks, so caution is needed in determining whether chest discomfort or pain is angina pectoris. In recent years, foreign scholars have also emphasized that the term “angina” does not exactly represent pain, and that the patient’s sensation of myocardial ischemia and hypoxia may be something other than pain, and thus may deny feeling pain. The following aspects can help to clinically identify angina: 1. Nature: angina should be crushing, constricting, pressing, suffocating, heavy, smothering pain, rather than a sharp, knife-like pain or grasping pain, a short pinprick-like or electric shock-like pain, or a feeling of chest tightness around the clock. In a few patients, it may be a burning sensation, a feeling of tension or shortness of breath with a tight squeezing sensation in the throat or over the trachea. The pain or discomfort is light at the beginning, gradually increases and then gradually disappears, and is rarely affected by position change or deep breathing. 2. Location: The pain or discomfort is often located in or near the sternum, and can also occur at any level between the epigastrium and the pharynx, but rarely above the pharynx. Sometimes it can be located in the left shoulder or left arm, and occasionally in the right arm, jaw, lower cervical spine, upper thoracic spine, left interscapular or suprascapular area, however, it is rarely located in the left axilla or under the left chest. 3. Time limit: 1-15 minutes, mostly 3-5 minutes, occasionally up to 30 minutes (except for intermediate syndrome), pain lasting only a few seconds or discomfort (mostly boredom) lasting all day or several days are not like angina. 4, triggering factors: mostly physical exertion, followed by emotional excitement, climbing a building, walking fast on a flat surface, walking after a full meal, walking against the wind, even the slightest movement of forceful defecation or raising the arm over the head, exposure to cold environment, eating cold drinks, pain in other parts of the body, and emotional changes such as terror, tension, anger, worry, etc., can be triggered. Physical activity plus emotional activity is more likely to induce. 5, the effect of nitroglycerin: sublingual containing nitroglycerin tablets if effective, angina should be relieved within 1 to 2 minutes (also need 5 minutes, to take into account that some patients may not have an accurate estimate of the time). In prone angina, nitroglycerin may not be effective. In assessing the effect of nitroglycerin, attention should also be paid to whether the drug used by the patient has failed or is close to failure.