If patients have chest tightness at night, there are several factors: 1. The most common factor is cardiogenic factors, such as coronary atherosclerotic heart disease, unstable angina pectoris, myocarditis, pericarditis, heart valve disease, hypertrophic obstructive cardiomyopathy, the above cardiogenic factors will lead to chest tightness and shortness of breath due to ischemia and lack of oxygen in cardiac muscle cells, especially at night when sleeping. 2, respiratory system diseases, such as chronic bronchiectasis, chronic obstructive emphysema, chronic pulmonary heart disease, pulmonary hypertension and other conditions will also appear in the arterial blood oxygen saturation during sleep, the body will also appear lack of oxygen, due to lack of oxygen will also lead to chest tightness. 3, plant nerve dysfunction, sleep at night will also have clinical symptoms and performance of chest tightness.