Coughing is a protective reflex action, and the cough reflex is usually effective in removing secretions from the respiratory tract or foreign bodies that have entered the airway. The causes of coughing include disease and non-disease factors. 1. Common non-disease causes (1) Exposure to substances that irritate the throat: e.g. irritating gases (hot and cold air, bromine, ammonia, etc.), tobacco (odor), particulate dust, smoke, etc. (2) Drinking and eating too quickly: tends to cause choking. (3) Taking angiotensin-converting enzyme inhibitors: the drug will lead to an increase in the synthesis of inflammatory mediators such as histamine and prostaglandins, which will irritate the mucous membrane of the trachea, thus causing cough. (4) Pleural cavity puncture: this may be due to irritation of the bronchial tubes by thoracic puncture. (5) Autonomous control of coughing: when feeling a foreign body or phlegm in the throat, control the occurrence of coughing by oneself. 2. Common causes of diseases: respiratory infections, pulmonary vascular diseases, respiratory tumors, pleural diseases, circulatory diseases, digestive diseases such as gastroesophageal reflux disease, neurological diseases such as encephalitis and meningitis. There are many causes of cough, and long-term recurrent cough is mainly caused by diseases, only the common disease causes are listed above. For coughs that are not caused by diseases, it is necessary to consult a doctor to clarify the cause and take appropriate measures to deal with the cause.