When coughing after lying down, it is usually necessary to consider the following three aspects: 1. The cough may be caused by reflux of gastric contents after lying down, resulting in stimulation of the nerves in the throat. 2. 4. People who often smoke and have worked in dusty and polluted mines often have a cough that occurs easily when they lie down at night. When the body is lying down, the abdominal organs and diaphragm are elevated, leading to restricted lung diastole, and then the coughing phenomenon will be significantly aggravated.