The factors that cause drooling in bed are the following categories: first, oral hygiene factors, if you have the habit of not brushing your teeth before going to bed, the food residue left in your mouth will react in the gaps between your teeth and produce bacteria, bacteria will cause damage to normal teeth, periodontal and gum, producing oral diseases such as periodontal disease, gingivitis, dental caries, etc. These diseases will affect the phenomenon of drooling in sleep, it is recommended to develop Good oral hygiene habits, brush your teeth before going to bed. Second, certain congenital malformations of the teeth, malformed teeth in sleep will stimulate salivary gland secretion, will also cause the phenomenon of sleep drooling, it is recommended to go to the dentist to correct the malformed teeth. Third, neurological factors, if suffering from some neurological dysfunction, such as plant nerve dysfunction, will stimulate salivary gland secretion at night, the occurrence of drooling in bed.