In patients with stable angina, the degree of coronary circulation blood flow disturbance is mild, and temporary myocardial ischemia occurs when the cardiac workload is temporarily increased, and there are no obvious symptoms after the load is lifted. This type of angina is often triggered by one of the following triggers: labor, emotional stress, a full meal, cold, or painful irritation. The typical symptoms of angina pectoris during an attack are episodic chest pain, tightness and discomfort in the chest, which may spread to the left shoulder and the inner side of the left upper arm and last for several minutes or more than 10 minutes, accompanied by sympathetic excitement such as increased heart rate, increased blood pressure, sweating and panic. The angina can be relieved quickly after removing the trigger, resting or taking nitroglycerin.