Why Do People Drool in Their Sleep?

It may seem a little embarrassing: You wake up and your pillow is drenched in slobber. After you wipe the spit at the corners of your mouth, you might wonder, Why do we drool in our sleep?

This article explains some of the most common causes of drooling in sleep and what you can do about it.

Woman sleeping in her bed at home - stock photo

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Reasons for Drooling 

The body normally makes more than a liter of saliva per day. It is produced by salivary glands and is usually swallowed and re-absorbed into the bloodstream. Drooling occurs when the saliva collects within the mouth and, rather than being swallowed, it drips or runs out past the lips. Why might this occur more at night?

Open Mouth

The muscles of the body relax during sleep, especially during REM sleep. It's possible that your mouth is falling open as you sleep. Some suggest that sleep position may matter. Sleeping on your side may make it more likely that you will leak saliva.

The simplest answer is that you drool during sleep because your mouth is open.

Nasal Congestion

One of the biggest reasons your mouth could open during sleep is that you can’t breathe well through your nose. If you're congested because of a cold or allergies, you may begin to breathe through your mouth. If this occurs in sleep, saliva may drool onto the pillow.

A deviated nasal septum can also be to blame. Inside your nose, a thin wall called a septum separates one side of your nose from the other. If you're born with an off-center or uneven septum, airflow on the narrower side could be partly blocked.

As a result, you may snore or develop sleep apnea, a condition in which your breathing pauses during sleep. Both of these conditions could cause nighttime mouth breathing.

Excessive Salivation

Some people produce excess saliva, a condition called sialorrhea. Sialorrhea can be caused by certain medications. It can also happen as a result of a brain injury, stroke, Parkinson's disease, or another neurological condition. These conditions can make it harder to swallow. If you have a hard time swallowing, you may drool during the day, too.

Excess saliva can also be related to gastroesophageal reflux disease (GERD) or heartburn at night.

Treatment Options 

In general, it is not necessary to treat drooling that happens while you sleep. It may be annoying, but won’t lead to dehydration, infection, or other problems.

Depending on your symptoms, nasal congestion may need treatment. And if you notice symptoms of sleep apnea, it's a good idea to have an evaluation for this condition.

When drooling happens because of a health condition that impairs swallowing, your healthcare provider may prescribe atropine drops or scopolamine patches.


Drooling during sleep isn't uncommon and may not be a sign of a health problem. It can happen because you're breathing through your mouth instead of your nose. Congestion, your nasal anatomy, and sleep apnea can cause you to breathe through your mouth.

Sometimes people produce more saliva than they can swallow. Medications can cause this kind of overproduction. Some health conditions make it harder to swallow, too, leading to drooling throughout the day.

If you are concerned about what's causing you to drool, speak with your healthcare provider to see if you need further evaluation and treatment.

Frequently Asked Questions

  • Can medication cause you to drool in your sleep?

    Yes. Hypersalivation can be caused by certain prescription drugs such as clozapine, an antipsychotic drug. Medications for Alzheimer’s disease, myasthenia gravis, or other diseases may also cause excess saliva and nighttime drooling.

  • How can I get rid of mouth pain and extra drool?

    If you have excess saliva and pain in your mouth or gums, you may have an infection or cavity in your teeth. Creating more saliva is one way the body might try to fight off an infection in the mouth. See your dentist for a cleaning and thorough check up.

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4 Sources
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  1. Shah JA, George A, Chauhan N, Francis S. Obstructive sleep apnea: Role of an otorhinolaryngologist. Indian J Otolaryngol Head Neck Surg. 2016;68(1):71-74. doi:10.1007/s12070-015-0922-8

  2. Lakraj AA, Moghimi N, Jabbari B. Sialorrhea: anatomy, pathophysiology and treatment with emphasis on the role of botulinum toxinsToxins (Basel). 2013;5(5):1010–1031. doi:10.3390/toxins5051010

  3. Essali A, Rihawi A, Altujjar M, Alhafez B, Tarboush A, Alhaj Hasan N. Anticholinergic medication for non-clozapine neuroleptic-induced hypersalivation in people with schizophrenia. Cochrane Database of Systematic Reviews. 2013 Dec;19(12):CD009546. doi:10.1002/14651858.CD009546.pub2

  4. Adadan Güvenç I. Sialorrhea: a guide to etiology, assessment, and management. In: Adadan Güvenç I, ed. Salivary Glands - New Approaches in Diagnostics and Treatment. IntechOpen; 2019. doi:10.5772/intechopen.82619