Many children have normal symptoms during the day but cough constantly at night for a variety of reasons, such as bronchitis, upper respiratory tract infections, laryngitis, allergic cough, improper sleeping position, and lack of ventilation in the room. When children have respiratory infections, they often do not cough during the day or cough less if the condition is not very serious, and they cough more often at night and make coughing sounds because it is more difficult to cough up airway secretions during sleep. Coughs caused by upper respiratory tract infections are more active during the day, but at night, when the child is asleep, the irritation to the throat is greater, thus causing a cough at night. Laryngitis is mainly due to inflammation of the throat or dryness and itching that irritates the airways and causes a cough at night. Babies also tend to cough at night if they have more snot. This is due to the fact that lying flat at night the snot may back up and irritate the throat causing the child to cough. Allergic cough usually occurs in the spring, when the baby is allergic and suffers from persistent or recurrent violent coughing after being stimulated by pollen. Coughing may also occur due to poor lung or bronchial breathing caused by improper sleeping position, and is accompanied by other symptoms such as breath-holding and tearing. Insufficient oxygen in the room due to lack of ventilation can also cause children to cough at night. If your child coughs more frequently at night and has other symptoms such as asthma, you should go to the hospital for a checkup to rule out other diseases.