What causes drooling during sleep that also has a bad smell?

Under normal circumstances, saliva refers to oral secretions. Excessive salivation during sleep accompanied by a foul odor may be caused by poor lifestyle habits, indigestion, oral ulcers, chronic periodontitis, or facial nerve paralysis. It is recommended to seek medical attention promptly to determine the underlying cause and receive appropriate symptomatic treatment under the guidance of a qualified physician. Specific analyses are as follows:

1. Poor Lifestyle Habits

Sleeping in improper positions without adequate oral hygiene may lead to drooling and bad breath during sleep. It is advisable to thoroughly clean the teeth before bedtime to prevent bacterial growth.

2. Indigestion

Consuming excessive amounts of food or hard-to-digest meals at dinner may result in indigestion. During sleep, gastrointestinal motility continues, which may reflexively trigger contraction of the masticatory muscles, leading to increased salivary secretion that leaks from the corners of the mouth. Additionally, undigested food in the stomach and intestines may produce foul gases that rise into the oral cavity, causing bad breath and foul-smelling saliva. Adjust dietary habits by avoiding overeating at night and reducing or eliminating consumption of hard-to-digest foods.

3. Oral Ulcers

Oral ulcers are typically caused by damage or erosion of the oral mucosa. Mucosal injury may cause pain and a burning sensation, increasing saliva production during sleep. Moreover, ulceration may lead to foul-smelling saliva. This condition is often accompanied by symptoms such as redness, swelling, and pain. It is recommended to follow a doctor's instructions to use medications such as ethacridine lactate solution, oral ulcer powder, and vitamin C tablets for treatment.

4. Chronic Periodontitis

Chronic periodontitis is a slowly progressing infectious disease of the periodontal tissues caused by bacteria. During sleep, gum discomfort may cause unconscious mouth opening and increased salivation. Bacterial proliferation can result in foul-smelling saliva. Common accompanying symptoms include gingival edema, bleeding, and pus discharge. It is recommended to follow medical advice and use medications such as metronidazole tablets, tetracycline tablets, or succinate erythromycin tablets for treatment.

5. Facial Nerve Paralysis

Facial nerve paralysis is a neurological deficit caused by damage to the facial nerve. Nerve impairment may lead to unilateral drooping of the mouth corner, slurred speech, and may also affect salivary gland secretion and the ability to close the mouth properly, resulting in excessive salivation with an unpleasant odor during sleep. Other common symptoms include widened eye fissures and air leakage while speaking. It is recommended to follow a doctor’s instructions to use medications such as prednisone acetate tablets, dexamethasone acetate tablets, and acyclovir tablets for treatment.

In daily life, maintaining good oral hygiene and developing consistent tooth-brushing habits can effectively help prevent foul-smelling saliva secretion.