Coughing at 3 o’clock at night may be caused by physiological reasons, such as inhalation of cold air, dust and other causes of transient coughing, but also may be caused by pathological reasons, such as cough variant asthma, lung infection, gastroesophageal reflux or cardiac insufficiency. 1. Cough variant asthma, nocturnal paroxysmal cough is its typical symptom manifestation, due to the increased excitability of the vagus nerve at night, there may be coughing more than 3 o’clock at night. 2. Lung infection, mainly refers to pneumonia and other infectious diseases of the lungs, sputum is not easily discharged at night when you sleep, and coughing may also occur. 3. Gastroesophageal reflux, due to the reflux of gastric juice and gastric contents after lying down, irritating the throat area and causing irritating cough symptoms. 4. Cardiac insufficiency, the heart local circulation obstacle, pulmonary stasis aggravation, can trigger the night cough symptoms. Coughing at 3 o’clock at night may also be seen in other diseases, the specific causes need to be clarified after medical examination, and at the same time in accordance with the doctor’s instructions for treatment.