If a child coughs at night but not during the day, there are many causes of coughing at night. If the cough is not particularly frequent at night, it is usually caused by physiological factors, such as environmental stimulation, strenuous exercise, nervous activity, inhalation of foreign bodies, mental changes, etc. If the cough is frequent at night, it is mostly considered to be caused by pathological factors, mainly including cough variant asthma, cold, heart diseases, gastroesophageal reflux, etc. I. Physiological factors 1. Environmental stimulation: the lower temperature at night and the fact that the doors and windows are usually closed at night when sleeping makes the air uncirculated and dry, which can easily lead to a child’s cough at night; 2. Strenuous exercise: children who exercise strenuously before going to bed, thus leading to a lack of water in their bodies and shortness of breath, can easily trigger a cough at night; 3. Nervous activity: the increased activity of the cholinergic system in the bronchial glands at night This causes an increase in glandular secretion, which stimulates children to cough at night. During the daytime, sympathetic nerve activity increases, gland secretion decreases, and children’s coughing is weakened; 4. Inhalation of foreign substances: bedding is not changed and cleaned in a timely manner, and children may inhale similar dust mites, dust, and animal dander when resting at night, leading to coughing at night. It is recommended that attention be paid to the timely change of bed sheets and covers; 5. Spiritual changes: children have nightmares at night, which may also induce coughing. Second, pathological factors 1, cough variant asthma: is a kind of children’s respiratory disease with cough as the main symptom, cough usually occurs at night, the cough is not obvious during the day, may also be accompanied by chest tightness, shortness of breath; 2, cold: children have a fever and cold, coupled with the lower temperature at night, so the symptoms of cough at night can easily appear, can be treated by nebulization or drugs to help relieve the symptoms of cough. In addition, during the day, due to gravity, phlegm is below the airway, and at night in the lying position, secretions in the child’s airway move upward thus blocking the airway, and coughing at night becomes more obvious, resulting in coughing at night and not during the day; 3. Heart diseases: such as congenital heart disease, the pumping function of the child’s heart is reduced, and pulmonary circulation is prone to stasis at night when sleeping in the lying position, thus resulting in the child coughing at night and not during the day 4. Gastroesophageal reflux: If children sleep in the horizontal position at night, if gastroesophageal reflux occurs, it is easy to produce throat and tracheal irritation, which leads to coughing at night and not during the day.