Why do We Drool While We Sleep?

Mary McMahon
Mary McMahon

People drool when they sleep because they have difficulty swallowing saliva or retaining it while they are not conscious. People with excess saliva production or drooling problems while awake may suffer from significant problems related to it while sleeping. There are health concerns associated with the production of excessive saliva that lead some people to pursue treatment to address the issue. Treatment can be provided by a general practitioner, neurologist, or other medical specialists, depending on the underlying cause.

Pregnant women typically produce more saliva than usual.
Pregnant women typically produce more saliva than usual.

The salivary glands are in continuous production, generating saliva to lubricate the mouth. Saliva production increases when people eat. The mouth is designed to help people retain this liquid, and people regularly swallow to allow it to drain into the stomach so it can be eliminated from the body. While asleep, the mechanisms for keeping saliva in the mouth and swallowing it may not function as well; swallowing reflexes, for example, can be less active.

Side effects of certain medications may include excessive drooling.
Side effects of certain medications may include excessive drooling.

In babies, drool during sleep is very common because the reflexes involved have not formed and been refined yet. In adults, some drooling is normal, but excessive amounts can be a sign of an underlying medical problem. People with certain neurological disorders can have difficulty managing their saliva while sleeping or awake. Parkinson's disease, cerebral palsy, stroke, facial paralysis, and Alzheimer's disease can all be associated with this problem. Pregnant women can also start producing more saliva than usual.

People may drool while they sleep because of medications or sickness.
People may drool while they sleep because of medications or sickness.

People may also find that they experience drooling while sleeping when they are not feeling well. For these individuals, there may be a spike in saliva production associated with a period of ill health, followed by a reduction. Certain medications can also increase saliva production and lead to drooling that becomes more noticeable during sleep. If people notice that they appear to be producing more saliva than usual or that they have trouble retaining it, they may want to bring it up with a medical professional to discuss possible causes and treatment options.

In addition to soiling bedclothes, drooling can become a problem because people may be at risk for inhaling the fluid or developing other problems. There are some medications that can sometimes address this problem, and patients sometimes also benefit from physical therapy to develop stronger reflexes. Such therapy can also help people with speech and eating if they are experiencing difficulties. Surgery on the salivary glands can be another option, although it is usually a treatment of last resort.

Drool during sleep is quite common in babies.
Drool during sleep is quite common in babies.
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


I have to get up and change clothes three or four times a night because it looks like someone poured a bucket of drool on me. I'm talking gallons per night and that's not an exaggeration. I sleep sitting up because of apnea and I wake up with my whole upper body drenched. If I do happen to lie down, I wake up literally drowning in drool. I mean it's like I was standing in the pouring rain. I've told countless doctors about this but none seem to have a clue. I start to drool as soon as I close my eyes. My mouth isn't even open. So whatever your problems with drooling might be, the chances are they aren't like mine. But then again, that's just one of two dozen problems I have that no one else has.


@dautsun - That's a really good point. The treatments for a lot of those conditions have improved a lot over the last few years, so it's even more important to catch things as quickly as possible. I also had no idea that drooling could be a sign of any of those things either.


I had no idea that neurological conditions like Parkinson's disease, stroke, and Alzheimer's could cause excessive drooling while the person is asleep. I think this is really good information to have if you are a caretaker for an older relative.

That way, if you noticed the person you're caring for is drooling much more than usual, you can take them to the doctor. I feel like some conditions can start with seemingly normal forgetfulness, so if you notice something out of the ordinary like drooling, it might help your family member get diagnosed sooner rather than later.

@JessicaLynn - Yeah, most people don't want to admit they drool in their sleep a little, but it is perfectly normal. I remember when I was younger I used to get really embarrassed if I had a boyfriend stay over and noticed in the morning I had drooled a bit in my sleep. But I later realized there's nothing to be embarrassed about, because everyone does it.

@tinguli - If you are drooling a lot in your sleep along with blood, you should probably pay your doctor a visit. You might be experiencing some kind of medical problem, and the Internet can't really diagnose you.

Anyway, as the article said, some drooling with you sleep is normal, but not an excessive amount. I usually drool a little bit in my sleep, and I've noticed I always drool more if I have some kind of upper respiratory condition, or a really sore throat. I think that's because it hurts to swallow when you have a sore throat, so my body resists doing it.


I don't normally drool, but I do recall an episode of drooling once when I had been sleep deprived for two days. I went on vacation with my aunt and uncle, and my uncle snored so loudly that I couldn't sleep for two nights in a row.

By the third day, I was so tired that I passed out in the hotel in the middle of the afternoon. Since he wasn't asleep at the time, there was no snoring to keep me awake. I woke up hours later with dried drool caked all over my face, and I felt so much better!


I am wondering if drooling is related to snoring. My husband has gained thirty pounds over the last three years, and this has made him snore. It has also increased the amount of drool on his pillow.

I believe that he has always slept with his mouth open, but it seems that maybe the loud snoring is forcing more saliva out. He might also have sleep apnea, which might be influencing the drool.

He is dieting right now and hoping to lose the weight. It will be interesting to see if his drooling decreases with his weight as the snoring becomes less pronounced.


@shell4life – I think that girls drool as much as boys, but it just depends on the individual. Drooling isn't influenced by gender.

I think that the more relaxed a person is while sleeping, the higher the likelihood that they will drool. I have friends who are very anxious, and they never seem to drool, while my laid back friends drool puddles!


Do boys drool more than girls? I have noticed that whenever my son's little friends spend the night, the pillowcases are covered in drool the next morning, but when my little girl's friends stay over, I never see any.


I am having the same problem. Drooling! Mine is worse because I love using white bed sheets and embarrassingly, most of the mornings my pillow is full with these blood stained marks. It is about six months today when I first noticed it when I slept in my friend's apartment. I am very uncomfortable with it and it now happens almost every day. Can someone help?


For volunteer work, I used to assist an acupuncturist perform treatments in under served communities. One thing that I noticed was that almost everyone would drool after their treatment. The treatments were only half hour communal treatments, but they seemed like they would wash people's stresses away. It was a really nice thing to see people be so happy.


I never realized that drooling in the sleep could lead to the point of surgery or treatment. I drool on occasion, but only when I finally get a good nights sleep after a marathon month. I never realized drool could kill you though.

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