Patients who cough particularly badly at night may be caused by the following reasons: 1. The vagus nerve is more excited at night, and the bronchial smooth muscle contracts more strongly, which increases respiratory secretions and causes a cough reflex, so the cough is more severe at night. 2. Wind and cold: Because the temperature is lower at night and the air is dry, it is easy to invade the respiratory tract and cause mucosal irritation and bronchospasm, thus 3. heart disease: especially for patients with nocturnal paroxysmal dyspnea, hypertension, diabetes, coronary artery disease, etc., the possibility of acute heart failure should be excluded. 4. cough variant asthma: a bronchial excitation test can be improved to clarify the diagnosis. 5. when suffering from reflux esophagitis, gastric acid reflux to the throat occurs when lying down at night, so a severe cough at night can occur. This can lead to a severe cough at night. If the cough is more pronounced at night and shortness of breath and airway spasm are evident, it is still recommended to visit the emergency department of the hospital to identify the cause before using medication.