1, the site of pain: angina occurs when the pain site is mainly located in the posterior sternum or left anterior chest area, there is a palm-sized range, or even across the entire chest, the boundaries are not very clear. Pain can sometimes be manifested as epigastric pain, sometimes radiating to the jaw, and sometimes to the waist and legs. In addition, the pain may even radiate to the left shoulder, the left inner arm up to the ring and little fingers or the entire left upper extremity during an angina attack. It is because of the wide range of pain in angina that it is easy to misdiagnose. 2, the nature of pain: angina attack pain is not a strong sharp pain, but a dull pain, chest pain often have pressure, tightness, stuffiness, burning sensation, but not sharp, unlike knife or needle-like pain. Occasionally, it is accompanied by the fear of dying. Patients often unconsciously stop the original activity during the attack until the symptoms are relieved. 3, the pain attack time and duration: the attack time of angina varies according to the classification of angina. Stable angina attack often no trigger; exertional angina often occurs during exertion or emotional excitement, including full meals, defecation can be triggered, some episodes are longer, the number of episodes is also more frequent; variability of angina often in the midday or early morning sleep regularly attack. The duration of an angina attack is usually 3-5 minutes, and in severe cases it can be 10-15 minutes. Angina can occur once in a few days or weeks, or several times in a day. 4, relief mode: generally can be relieved after stopping the original symptom-triggering activities, sublingual nitroglycerin can also be relieved within a few minutes. Because the clinical manifestations of angina pectoris are complex and the range of pain is wide, it is important to go to the hospital for timely consultation when pain occurs so as not to delay the condition and treatment.