Sleeping at night and coughing during the day without coughing can be seen in both physical factors such as change of position, vagus nerve excitation, and respiratory pathology such as asthma. 1. Change of body position: During the daytime, if you feel phlegm, it is natural to discharge it. At night, when sleeping, due to the lying position, the mucus secreted by the glands is not easy to be discharged, and it is a continuous stimulation to the respiratory tract, so it is easy to cough. 2. Vagus nerve excitation: the vagus nerve is more excited at night, the result of its action is to promote the secretion of the glands, the secretion accumulated in the trachea, the stimulation of the trachea will cough. 3. Disease factors: (1) Asthmatics have hyperresponsive airways, which cause coughing at the slightest stimulus, and their most prominent feature is that the symptoms worsen at night and are mild during the day. (2) Gastroesophageal reflux disease (GERD) patients, when lying down at night, stomach acid reflux to the pharynx, stimulating the pharynx to produce dry cough symptoms. (3) Heart failure patients with pulmonary circulation stagnation, coughing symptoms may also occur at night when lying down. (4) Rhinitis and other patients with nasal secretions, night due to position changes, nasal secretions backflow stimulation of the throat, can also lead to night cough. 4. In addition, a closed sleeping environment at night may also cause coughing due to lack of air circulation. Therefore, it is important to maintain a well-ventilated environment. If the cough keeps recurring, it is recommended to seek medical attention as soon as possible.