Drooling during sleep is mainly due to the following reasons: first, and sleep position, some patients like to sleep in a prone position, resulting in the saliva produced in the mouth can not be swallowed in time to enter the stomach, from the corners of the mouth out of the normal situation, no special treatment. Second, dyspepsia, dyspeptic patients will have bad discomfort in the stomach, resulting in increased saliva secretion in the mouth and drooling, patients can also be accompanied by abdominal distension, loss of appetite, acid reflux, heartburn and other symptoms, it is recommended to go to the gastroenterology department for consultation. Third, patients with facial palsy, divided into central facial palsy and peripheral facial palsy, mainly manifest as poor closure of the corners of the affected side of the mouth, causing saliva to flow out from the corners of the mouth. Patients mainly manifest as crooked mouth and eyes, incomplete eye closure, and stored food between teeth and buccal mucosa, and it is recommended to go to the neurology department for consultation.