If a patient feels chest tightness and shortness of breath frequently when sleeping, first of all, cardiac insufficiency should be excluded. In patients with cardiac insufficiency, blood from the lower extremities will flow back to the lungs and even to the heart during sleep because the septal muscles will be elevated, and the heart rate will slow down due to sympathetic inhibition and vagus nerve excitation, and the lungs will also become less dilated. Therefore, for patients with cardiac insufficiency, if there are no obvious symptoms in normal life, but chest tightness, shortness of breath and other discomfort during sleep, it is highly suggestive of pulmonary stasis and cardiac insufficiency. Such people should go to the cardiology department of the local hospital for an electrocardiogram and cardiac ultrasound to determine whether there is significant myocardial ischemia and ST-T changes on the electrocardiogram, and also for cardiac ultrasound to determine whether there are structural changes. Structural changes in the heart include enlargement of each atrium, moderate to severe regurgitation of multiple valves, and a decrease in the ejection fraction of the heart. If one or more of these changes are present, the patient is considered to have severe cardiac insufficiency. In this case, the patient should take diuretics, ACEI drugs, beta-blockers, and aldosterone inhibitors.