Lying down and feeling chest tightness and breathlessness may be caused by heart disease, respiratory disease, gastroesophageal reflux disease and other factors, you should consult a doctor in a timely manner to clarify the cause of the disease and then treat it. 1. Heart disease: common heart diseases that can cause chest tightness and breathlessness when lying down are unstable angina and heart failure. (1) unstable angina: and the heart supply blood to the coronary arteries atherosclerosis has occurred leading to insufficient blood supply to the heart, the patient will have a lie down to feel chest tightness and breathlessness, sweating, nausea, vomiting and other symptoms, can be in the doctor’s use of aspirin, nitroglycerin and other drugs. (2) heart failure: heart or other causes of heart pumping dysfunction, the patient will have a lying down chest tightness and breathlessness symptoms, can be accompanied by lower limb edema, can use diuretics, vasodilator drugs for treatment, such as furosemide, nitroglycerin and so on. 2. Respiratory diseases: chest tightness and breathlessness can also be seen in asthma, chronic obstructive pulmonary disease and other respiratory diseases. Asthma patients have a history of previous attacks and family genetic history, patients with chronic obstructive pulmonary disease have a long history of smoking, such people should consult a doctor in a timely manner to determine the cause of the disease. 3. Gastroesophageal reflux disease (GERD): many factors lead to gastric contents into the esophagus, patients will have a chest tightness and breathlessness when lying down, heartburn, foreign body sensation in the throat and other symptoms, and can be treated with medicines such as omeprazole and mosapride. All of the above drugs should be used under the guidance of a doctor, and should not be used blindly on their own.