The reason for a strong morning cough in bronchitis is that bronchitis is due to congestion, edema, and increased secretions in the bronchial mucosa caused by bacterial and viral infections. Coughing is a self-healing defense response of the organism, which is trying to expel secretions and inflammatory substances from the airways by coughing. At night, when the body sleeps, the body’s center makes the sympathetic nerves suppressed, the vagus nerves are excited, and all other functions are inhibited, mainly at night for the body to rest well, and the body’s coughing self-cleaning effect is weakened. After a night’s rest, the secretions and phlegm in the airways will increase. In the morning, when the sympathetic nerves are excited and the secretions in the airways accumulate, the body will accelerate the coughing and phlegm-removal action in order to breathe smoothly. This is why patients with bronchitis will get up in the morning and cough and cough up more phlegm, which is also a self-cleaning effect of the human body and a regulatory effect of the human body’s functions. The cough is aggravated in the morning because after a night’s rest, the secretions in the airways increase and the coughing is accelerated in the morning, which is the effect of phlegm discharge.