Daytime is fine night old cough may have a variety of causes, common causes are bronchial asthma, left heart failure. 1. Bronchial asthma: asthma in the cough variant asthma patients, if at night exposure to allergens that cause coughing, such as pillowcase dust mixture, etc., can be manifested as a violent paroxysmal cough. Therefore, coughing at night and nothing during the day, should pay attention to the presence of asthma, should go to the hospital for further examination, clear diagnosis and allergens. 2. Left heart failure: heart failure causes lung stasis or edema, coughing can occur at night when sleeping, and can be slowly relieved after sitting up. Patients with previous coronary heart disease or hypertension should be alerted. It should be noted that the daytime is fine at night old cough, should be to the local hospital to improve the examination, after a clear diagnosis by a professional doctor for standardized treatment.