Cough is a protective measure of the human body and is a common clinical symptom of respiratory tract infection. The phenomenon of coughing when lying down is more common in clinical practice, which is caused by a variety of reasons, mainly may be viral, bacterial infections and foreign body irritation. There are very many diseases that cause coughing when lying down, and the more common ones are bacterial infections and viral infections, and the more common ones are bronchitis, bronchitis, pneumonia, pharyngitis, pharyngolaryngitis, etc. When suffering from the above-mentioned diseases, patients will have symptoms such as coughing and coughing phlegm, and when lying down, the phlegm in the respiratory tract moves and can stimulate the respiratory tract to cause coughing and coughing aggravation and acceleration; there are also heart diseases that may trigger coughing, and heart diseases are mainly considered to be heart failure, and patients have coughing, cannot lie down and show telangiectatic breathing; reflux esophagitis may also stimulate the throat because of reflux This causes coughing, which is aggravated by severe reflux after lying down. When coughing when lying down, patients need to go to the hospital to actively identify the cause, and take anti-inflammatory, anti-allergic, cough and phlegm treatment for different causes of the disease, such as patients taking anti-inflammatory drugs like Ambroxol, licorice tablets, cephalosporins, etc. for active treatment. In conclusion, the common causes of coughing when lying down are viral, bacterial infections and foreign body irritation. In addition to taking medication, patients need to increase nutrition, not to eat spicy and stimulating food, and to eat more fresh vegetables and fruits to improve their immunity, which is beneficial to the recovery of the disease.