What are the causes and symptoms of angina pectoris?

Angina pectoris often occurs in heavy physical labor, long-distance travel, emotional excitement, after a full meal, or when the weather is suddenly cold. Patients feel unbearable pain in the precordial region, which often radiates to the left arm, left shoulder, neck or left back. Pain has the feeling of squeezing, depression and contraction, and a few patients even have the feeling of fear and death, pale face and cold sweat. Generally, this kind of pain only lasts for 2 ~ 3 minutes, and at most it does not exceed 15 minutes.