The tightness of the heart may be caused by physiological factors such as overwork and nervousness, or it may be caused by angina pectoris, acute myocardial infarction and other diseases. 1. Physiological factors: overexertion, strenuous exercise, nervousness, prolonged late-night sleep, sleep deprivation, may lead to transient blood circulation disorders, the emergence of the heart feels tight. This kind of situation is a normal phenomenon, rest can be relieved. 2. Angina pectoris: angina pectoris is caused by a decrease in myocardial blood flow, resulting in myocardial hypoxia. Patients may have chest tightness, chest pressure pain, palpitations, dyspnea and other symptoms, manifested as a feeling of tightness in the heart. 3. Acute myocardial infarction: its etiology is related to factors such as decreased blood perfusion in the heart, insufficient oxygen supply to the heart muscle and increased oxygen consumption of the heart muscle. Patients may have symptoms such as chest tightness, dyspnea, shortness of breath, chest discomfort, etc., and some of the patients feel tightness in the heart. There are many reasons for the tightness of the heart, and it is recommended that patients go to a regular hospital and undergo a relevant examination in order to clarify the cause of the disease.