There are many reasons for drooling while sleeping, commonly found in the following points: 1, oral diseases: oral hygiene problems, resulting in the accumulation of food residues in the mouth, over time it is easy to cause gingivitis, periodontitis and other oral diseases, easy to sleep with more drool. 2, improper sleeping position: incorrect sleeping position will also cause more drool, such as sleeping on the table or lying on the side. 3, cardiovascular and cerebrovascular Diseases: especially brain diseases, is likely to lead to the central nervous system and the peripheral nervous system of the corresponding regulatory disorders, resulting in the brain to issue the wrong instructions, resulting in salivary gland secretion disorders, such as parotid glands, sublingual glands occur corresponding disorders, etc. 4, other diseases: obstructive sleep apnea hypoventilation syndrome, due to open mouth breathing, and then prone to increased saliva when sleeping. The specific causes of excessive drooling in sleep should be analyzed according to the individual differences and the actual situation of the patient. Patients are advised to seek medical attention as soon as possible. If the problem is due to cardiovascular or cerebrovascular problems, the cause should be clarified in a timely manner, and appropriate medication and control should be given to prevent adverse consequences. If it is caused by local factors of the oral cavity, the corresponding surgical treatment should be given for the cause, as well as the related drug treatment.