Frequent drooling in bed may be caused by oral inflammation, malocclusion, neuromodulation disorders, etc., as follows. 1. Oral inflammation: periodontitis and other inflammatory diseases will promote salivary secretion, when the secretion of saliva can have a salty flavor. 2. Dental deformity: severe maxillary protrusion patients can hardly cover the tooth surface during sleep, and the upper and lower lips are naturally separated, which leads to drooling. 3. Neuromodulation disorders: Certain neuroses or other systemic diseases that may cause autonomic disorders can lead to abnormal excitation of the parasympathetic nerves during sleep, causing increased salivary secretion. Frequent drooling in bed may have other reasons, it is recommended to go to the hospital in time, clear cause for targeted treatment.