Lying down chest discomfort, sitting can be more comfortable, may be due to lung disease, heart failure and other reasons. 1. Lung disease: it may be emphysema or pleural effusion, air pressure on the lungs and affect breathing, lying down can cause the diaphragm upward, the chest cavity is narrowed, resulting in a sense of compression in the chest, lying down chest discomfort, sitting can be more comfortable, the patient can go to the hospital to do CT lungs, or take a film of the lungs, lung function tests to clarify the cause of the disease. 2. Heart failure: when the patient’s chest is uncomfortable when lying down, but more comfortable when sitting, this kind of performance is mostly seen in heart failure, that is, congestive heart failure, especially at night, because generally when lying down, the patient’s return blood volume increases, and the burden on the heart increases, which may lead to the onset or aggravation of heart failure, and it is recommended that the patient go to the hospital for a cardiac color ultrasound, to assess the structure and function of the heart. Chest discomfort when lying down, it is recommended that patients seek timely medical attention, through the examination to clarify the cause of the disease, and cooperate with the doctor to actively treat, so as not to delay the condition.