The diagnosis of angina includes two main aspects: first, clinical symptoms, and second, ancillary tests. The typical symptoms of angina pectoris are dull or pressure-like, burning pain after the upper or middle part of the sternum, which can radiate to the left shoulder left inner arm, jaw or back. This kind of pain is sudden, mostly triggered after heavy physical activity or emotional excitement, and can also appear after adverse stimuli such as diet, cold, smoking, etc. The duration is relatively short, usually a few minutes, not more than 5 minutes, and most of the pain disappears within a minute with sublingual nitroglycerin. If angina pectoris lasts for a long time, it should be excluded from myocardial infarction, and most of them will have specific changes on the ECG, including ST-segment elevation, abnormally wide Q-wave and T-wave inversion.