Coughing during the day and not coughing at night may be caused by allergic cough, pneumonia, chronic pharyngitis and other reasons. 1. Allergic cough: When you go out during the day, you may come into contact with allergy-causing substances, such as pollen and willow flakes, which may cause coughing. At night there is no contact with such substances, so there is no cough at night sleep. 2. Pneumonia: Pneumonia is due to respiratory infectious diseases caused by coughing, generally more coughing in the daytime, not coughing at night when you sleep, because the deep sleep at night, the cough central nervous system is subject to a certain degree of inhibition, in the case of inactivity, and therefore sleep at night without coughing. 3. Chronic pharyngitis: If the patient has chronic pharyngitis and other diseases, it is possible to be exposed to irritating odors, cold air, etc. during the day, resulting in pharyngeal discomfort, causing coughing. Coughing during the day and not coughing at night can also be caused by other diseases, such as symptoms do not ease or aggravate, it is recommended that timely to the hospital for examination, to identify the causes of the cause and for the cause of the treatment.