Coughing after lying down is commonly caused by the following reasons: 1. Reflux esophagitis, because the patient has basic diseases such as flaccid cardia and chronic gastritis, the change of position can lead to a small amount of gastric contents reflux, stimulating the pharynx or even the airway through the esophagus causing coughing, it is recommended to check electronic gastroscopy and H. pylori test. After a clear diagnosis, treatment such as acid suppression, protection of gastric mucosa and increase of gastric power can be given. 2. Variable cough, mostly caused by allergic factors, mostly occurs at night and in the early morning. It is recommended to check lung function, blood count and allergen test, etc. After a clear diagnosis, antispasmodic, anti-allergic and wheezing treatment can be given. 3. Coronary heart disease, some special types of coronary heart disease can occur with coughing after lying down, especially Patients with cardiac insufficiency are recommended to check electrocardiogram, cardiac ultrasound, myocardial enzyme spectrum, electrolytes, blood routine, etc., which can be gradually relieved by effective diagnosis and treatment.