Drooling in Sleep in Babies and Kids: What’s Normal

Occasional drooling during sleep is common in babies, toddlers, and young children and usually harmless — it happens when the mouth falls open and swallowing slows, which is normal during deep sleep. The more useful question is why the mouth is open. Persistent nighttime drooling often points to mouth breathing, which can be caused by nasal congestion, allergies, or enlarged tonsils and adenoids. That matters because chronic mouth breathing during sleep can be a sign of sleep-disordered breathing, which affects sleep quality and can produce daytime irritability, poor concentration, and behavior that looks like inattention. Drooling is worth discussing with a doctor if it persists past around age four, if it started suddenly, if it affects only one side, or if it comes with snoring, pauses in breathing, or difficulty swallowing.

Key takeaways

Drool on the pillow usually means the mouth fell open while swallowing slowed in sleep. It is a sign of how a child is breathing and sleeping more often than a problem in itself.
Babies drool most. Saliva control usually develops between 15 and 36 months, and drooling is considered abnormal only after age 4.⁠⁷
Teething adds to it: drooling is one of the occasional symptoms of teething the American Academy of Pediatrics lists.⁠¹¹
A baby under one still sleeps on their back for every sleep, whatever the drool. The side position is as dangerous as the stomach, and nothing goes around the neck, teething necklaces included.⁠¹¹,⁠¹²,⁠¹³
A damp pillow most nights usually points to mouth breathing, most often from a blocked nose or enlarged tonsils and adenoids.⁠¹⁵
Snoring with pauses in breathing or gasping points toward sleep apnea, and the American Academy of Pediatrics recommends a sleep study for a child who snores and has signs of it.⁠⁴
In a randomized trial, the sleep study returned to normal within seven months in 46% of children with sleep apnea who waited without surgery, against 79% of those who had their tonsils and adenoids removed.⁠⁹
Drooling with a fever, difficulty breathing, choking, or a head held in an unusual position is a reason to contact the doctor.⁠¹⁰
Mouth taping is not a fix for a child: a 2025 systematic review found little evidence of benefit and possible serious harm, including asphyxiation when the nose is blocked.⁠¹⁴

Why do kids drool in their sleep?

Saliva production continues through the night. Swallowing slows during deep sleep. If the mouth is closed, saliva is managed automatically. If the mouth is open, it runs out.

So nighttime drooling is usually a downstream sign rather than a problem in itself. The question worth asking is what's keeping the mouth open.

Sleeping position. Side and stomach sleeping let gravity do the rest. If the drool is only ever on one side and matches how your child sleeps, that's often all it is.

A blocked nose. A child who can't breathe comfortably through their nose will breathe through their mouth. Colds, allergies, chronic rhinitis, and a deviated septum all do this. Allergies and sinus infections are both on the list of recognized causes of drooling.⁠¹⁰

Enlarged tonsils or adenoids. One of the most common causes of chronic mouth breathing in children. Adenoids sit behind the nose and aren't visible when you look in the mouth — which is why this is often missed at home. Swollen adenoids and tonsillitis both appear among the causes of drooling.⁠¹⁰

Oral motor differences. Lower muscle tone around the lips, cheeks, and tongue can make it harder to keep the mouth closed and manage saliva. This is more common in children with hypotonia or motor coordination differences. In children who are otherwise developing as expected, poor oral-motor control is one of the two factors a 2024 review found most often behind drooling.⁠⁸

Sensory differences. Some children have reduced awareness of the sensation of saliva in the mouth — an interoceptive difference — so the swallow that would normally happen automatically doesn't get triggered. Impaired oral sensation is the other factor that review names.⁠⁸

Tongue tie. A restricted tongue can affect resting tongue position, which affects both mouth closure and swallowing. See tongue ties and their symptoms in infants.

Teething, in younger children, temporarily increases saliva production. Drooling is one of the occasional symptoms of teething the American Academy of Pediatrics lists.⁠¹¹

Reflux. Increased saliva can be a response to acid. Gastroesophageal reflux disease is a recognized cause of drooling.⁠¹⁰

Some medications, including certain seizure and behavioral medications. Drooling is a recognized side effect of some medicines.⁠⁷,⁠¹⁰

When do kids stop drooling? What's normal at each age

A rough guide — variation is wide.

Birth to around 18 months — drooling is entirely expected. Swallowing coordination is still developing, and teething adds to it.
18 months to about 2 years — usually decreasing, still common during teething or concentration.
Around 2 to 4 years — most children have largely stopped daytime drooling. Occasional nighttime drooling remains common.
Past age 4 — persistent drooling, day or night, is worth mentioning to a doctor or dentist. Not an emergency, and not something to keep waiting out either.

Occasional nighttime drooling at any age can be entirely normal, including in adults. Frequency and pattern matter more than the fact of it.

The research sets out the expected window clearly. Drooling is common in typically developing babies and subsides between about 15 and 36 months as saliva control is established; it is considered abnormal after age 4.⁠⁷ A 2024 review of drooling in otherwise typically developing children adds the qualifier that matters for this page: it is drooling while awake beyond age 4 that should raise concern, and most of those children are managed with simple behavioral strategies and reassurance.⁠⁸ Toddlers who still drool now and then, especially asleep, are well inside the range. For what else to watch at this age, see the toddler guide.

Why do babies drool so much in their sleep?

Because they have not learned to manage saliva yet. Saliva control is a developmental skill, and in typically developing babies drooling is common until it is established, usually somewhere between 15 and 36 months.⁠⁷ Until then saliva collects at the front of the mouth and runs out whenever the mouth relaxes, and in deep sleep it relaxes. A wet patch under a sleeping baby's cheek is the expected result, not a sign that something is wrong.

Teething adds to it. The FDA, citing the American Academy of Pediatrics, lists drooling among the occasional symptoms of teething, along with mild irritability, a low-grade fever and an urge to chew on something hard.⁠¹¹ A pillow that is wetter during a teething stretch fits that pattern. For sore gums, the FDA suggests gently rubbing them with a finger or offering a firm rubber teether that is not liquid-filled.⁠¹¹

Is it safe to change how a drooling baby sleeps?

Not their position, and not with anything around the neck. Until their first birthday, a baby goes down on their back for every nap and every night, on a firm, flat surface with no soft bedding; the American Academy of Pediatrics' safe-sleep recommendations make no exception for drool.⁠¹²,⁠¹³ Its parent guidance calls the side position "just as dangerous as the stomach position," partly because a baby can roll from it onto the stomach.⁠¹³ The policy calls for a noninclined sleep surface, and the parent guidance says any surface inclined more than 10 degrees is unsafe, so propping the mattress or using a wedge to keep drool in is not an option.⁠¹²,⁠¹³ Nothing goes around the neck: the AAP advises against hanging a pacifier around a sleeping baby's neck,⁠¹³ and the FDA has received reports of deaths and serious injuries, including strangulation and choking, caused by teething jewelry such as amber necklaces.⁠¹¹

When baby drool is worth mentioning. On its own, it rarely is. Contact your baby's doctor if the drooling comes with gagging or choking, a fever, difficulty breathing, or a head held in an unusual position; MedlinePlus lists each of these as a reason to call.⁠¹⁰ Feeding difficulty and drooling that starts suddenly belong on the same list, as the red-flag list below explains.

How can you tell if your child is mouth breathing at night?

This is the part most articles skip, and it's the useful part.

If your child's pillow is regularly damp, they've most likely been sleeping with their mouth open. Occasionally, that's nothing. Consistently, it's worth a look — because chronic mouth breathing has effects well beyond the drool.

Other signs your child is mouth breathing at night:

Snoring, particularly loud or nightly
Waking with a dry mouth, chapped lips, or a sore throat
Restless sleep, frequent position changes, kicking off covers
Waking tired despite adequate hours
Dark circles under the eyes
Teeth grinding
Bedwetting past the expected age
Mouth resting open during the day, especially while concentrating

Your own observation counts. In a study of 93 children with moderate to severe sleep apnea, a parent's report that their child often or always breathed through the mouth was associated with nasal obstruction found on examination, and the authors concluded that a parent's diagnosis of mouth breathing is acceptable. In those children, mouth breathing was mainly related to a blocked nose.⁠¹⁵

Why it matters:

Sleep quality

Mouth breathing is associated with more fragmented, less restorative sleep, even without full obstructive sleep apnea.

Dental and facial development

Long-term mouth breathing has been associated with a narrower palate, a long-face growth pattern sometimes called "adenoid facies," and a higher rate of dental problems. Airway obstruction is described as potentially leading to dentofacial dysmorphogenesis, with how much depending on the child's age, how long it lasted and how complete it was.⁠⁵ One proposed mechanism is that the resting position of the tongue influences how the upper jaw develops — but a direct causal link isn't established, and genetics, allergies, and oral habits all play a part.

And it is not necessarily permanent

A study that recalled 57 people an average of 13 years after treatment for airway obstruction — some who had an adenoidectomy, some treated with medication — found significant long-term improvement in both groups across several facial measurements, including jaw angle, facial convexity and facial height.⁠⁵ Treating the obstruction is the point, not the drooling.

This is a reason to involve a dentist

Sleep-disordered breathing is under-recognized and under-diagnosed in children, and a scoping review of 34 studies makes the case that routine dental appointments are a practical place to screen for it.⁠⁶ A pediatric dentist sees the inside of your child's mouth on a schedule and can spot these patterns well before a parent would.⁠³

Daytime function

Poor sleep affects mood, attention, and behavior. More on this below.

Recurrent infections

Nasal breathing filters and humidifies air. Mouth breathing doesn't.

Can drooling in sleep cause a rash or dental problems?

The skin first. Skin that stays wet can break down: skin breakdown, odor and infection are among the recognized complications of chronic drooling,⁠⁷ and MedlinePlus advises watching for skin breakdown around the lips and chin in a child who drools a lot.⁠¹⁰ For a child who only drools at night, changing a damp pillowcase and gently drying the chin in the morning keeps the skin from staying wet. A rash that cracks, weeps or spreads is worth showing your pediatrician.

Then the teeth and gums. For teeth, the mouth breathing behind the drool is the bigger question. A 2026 meta-analysis of 13 studies found that children who mouth breathe have narrower upper dental arches at the canines and molars, a deeper palate toward the back of the mouth, and more posterior crossbite than children who breathe through the nose.⁠¹⁷ A systematic review of 11 studies linked mouth breathing with more gum bleeding, plaque and gum changes; its link with tooth decay was limited to early and advanced lesions.⁠¹⁸ Both compare children who already mouth breathe with children who do not, so they show which features travel together rather than proving that mouth breathing causes each one.

That is a reason to keep up regular dental visits rather than a reason for alarm. A pediatric dentist looks at the bite, the width of the arches and the gums, and can tell you whether a pattern such as an early malocclusion is developing. For the daily side of gum care, see brushing from the first tooth.

What are the signs of sleep apnea in a child who drools?

Habitual snoring is common enough that it is worth asking about: in a community pediatrics sample of 866 children aged 2 to 14, 16% snored habitually.⁠² The American Academy of Pediatrics' guideline on childhood obstructive sleep apnea is built around the two usual causes — enlarged tonsils and adenoids, and obesity — in an otherwise healthy child.⁠⁴ In young children the adenotonsillar route is the common one; in older children and adolescents, obesity becomes a leading contributor.

Signs that go beyond ordinary mouth breathing:

Loud snoring most nights
Pauses in breathing, gasping, or choking sounds during sleep
Sleeping in unusual positions — neck extended, propped up
Sweating heavily during sleep
Bedwetting that returns after a dry period
Very restless sleep
Difficulty waking, or excessive daytime sleepiness

The AAP guideline's first recommendation is that all children and adolescents should be screened for snoring, and that a child who snores and has other signs of obstructive sleep apnea should have a sleep study.⁠⁴ If you've noticed pauses in your child's breathing during sleep, say so specifically. That's the detail that changes the conversation, and parents often don't think to raise it.

How does poor sleep show up in a child's behavior?

Poor sleep affects children differently from adults. Where an adult becomes visibly tired, a child more often becomes irritable, hyperactive, impulsive, and unable to concentrate — a presentation that overlaps substantially with ADHD.

A population-based study followed around 11,000 British children, with parents reporting snoring, mouth breathing and witnessed pauses from 6 months onward and behavior measured at 4 and 7 years. Sleep-disordered breathing patterns predicted roughly 20% to 100% higher odds of behavioral difficulty, after controlling for fifteen potential confounders — and, strikingly, children whose symptoms peaked before 18 months and then resolved still showed 40% to 50% higher odds at age 7.⁠¹

A separate clinic study found hyperactivity roughly twice as common among children who snored habitually as among those who did not — 22% against 12%, an odds ratio of 2.2.⁠² That is an association between two things measured at the same time, not evidence that one caused the other. What it supports is narrower and more useful: asking about snoring belongs in any assessment for attention or behavior.

What that does mean: sleep is worth evaluating as part of any assessment for attention or behavior difficulties. Asking about snoring, mouth breathing, and sleep quality is reasonable, inexpensive, and easy to skip.

What it doesn't mean: that ADHD is usually misdiagnosed sleep apnea. That claim circulates widely and overstates the evidence. ADHD is a well-established condition, the two frequently co-occur, and treating a breathing problem doesn't mean the ADHD wasn't real.

The practical version: if your child has attention difficulties and snores, mouth breathes, or drools at night, mention the sleep signs during assessment. It's information the clinician needs and may not think to ask for.

Will my child outgrow sleep apnea, or need surgery?

Some children improve without surgery, and that is known from a trial rather than guessed. The Childhood Adenotonsillectomy Trial randomly assigned 464 children aged 5 to 9 with obstructive sleep apnea either to early removal of the tonsils and adenoids or to watchful waiting with supportive care. Seven months later, the sleep study had returned to normal in 46% of the children who waited, against 79% of those who had surgery.⁠⁹

Surgery did more than the sleep study shows: the children who had it had fewer symptoms and better behavior and quality-of-life scores than those who waited. What it did not change was the trial's main measure, a test of attention and executive function, on which both groups improved by a similar amount.⁠⁹ That fits the careful version of the attention question above. Treating a breathing problem can help a child sleep and behave better without being a cure for attention difficulties.

The trial enrolled children whose oxygen levels did not fall for long stretches during sleep, so it does not describe more severe sleep apnea.⁠⁹ For uncomplicated sleep apnea in an otherwise healthy child, the American Academy of Pediatrics guideline recommends removing the tonsils and adenoids as the first-line treatment when they are enlarged; CPAP, a mask that keeps the airway open with air pressure, when surgery is not done or the apnea persists afterward; weight loss alongside other treatment for a child who is overweight; and a nasal steroid spray as an option for mild sleep apnea when surgery is not possible.⁠⁴ Whether to wait or to operate is a decision for your child's ENT and pediatrician, made with a sleep study.

Is drooling a sign of autism or another condition?

Not on its own. Nighttime drooling in a child who is otherwise developing as expected is common and does not point to autism or any other diagnosis. Drooling becomes a sign worth following up when it comes with something else: drooling while awake past age 4, delays in speech, feeding or movement, or difficulty swallowing. A 2024 review notes that delayed saliva control can be an early indicator of developmental or intellectual delay, which is why daytime drooling past 4 deserves a look.⁠⁸

Some conditions make drooling far more common, usually because they affect the muscles and coordination of swallowing. In cerebral palsy, a meta-analysis of 42 studies estimated that 44% of people drool, with drooling more common the more a person's motor function is affected.⁠¹⁶ Cerebral palsy is the most common cause of problem drooling in children.⁠⁷ MedlinePlus also lists autism and Down syndrome among the nervous-system conditions that can cause drooling through difficulty swallowing.⁠¹⁰

Causes of drooling, and who to ask
Cause	What usually comes with it	First person to ask
Teething	Chewing on things, mild irritability, a low-grade fever⁠¹¹	Pediatrician or pediatric dentist
Blocked nose, allergies, sinus infection	Mouth breathing, congestion, snoring⁠¹⁰	Pediatrician
Enlarged tonsils or adenoids	Snoring, sometimes with pauses in breathing⁠⁴,⁠¹⁰	Pediatrician, then ENT
Throat infection: strep, tonsillitis, mononucleosis, peritonsillar abscess	Fever; drooling that starts suddenly⁠¹⁰	Pediatrician, promptly
Reflux (GERD)	Drooling alongside reflux symptoms⁠¹⁰	Pediatrician
A medicine	Drooling that began after a new medicine was started⁠⁷,⁠¹⁰	The prescriber
Oral-motor or oral-sensory differences	Drooling while awake past age 4, mouth often open⁠⁸	Speech-language pathologist or occupational therapist
Cerebral palsy and other neurological conditions	Delays in movement, feeding or swallowing⁠¹⁰,⁠¹⁶	Pediatrician, who may refer to a neurologist and a speech-language pathologist

When should my child's drooling be checked by a doctor?

When is a routine appointment the right step?

Book an appointment if your child:

Still drools regularly past around age four
Snores most nights
Mouth breathes during the day as well as at night
Wakes unrefreshed despite enough sleep
Has attention or behavior difficulties alongside any of the above
Has ongoing nasal congestion with no clear cause

When should you contact a doctor promptly?

Contact your child's doctor promptly if:

Drooling started suddenly in a child who wasn't drooling before
It affects only one side of the mouth, or you notice one-sided facial weakness
It comes with difficulty swallowing, coughing, or choking during meals
Your child has lost skills they previously had
You've noticed pauses in breathing during sleep
There's unexplained weight loss or feeding difficulty

Sudden onset and one-sided drooling are the two that warrant prompt attention rather than a routine appointment. Both can indicate a neurological cause that needs assessing.

Which doctor or therapist should check my child's drooling?

Your pediatrician — the right first stop. They can examine, assess for allergies and infection, and refer onward.

A pediatric dentist — can assess palate shape, bite, tongue position, and the dental signs of mouth breathing. Often the first professional to notice an airway pattern, because the changes show up in the mouth before they show up anywhere else.

ENT (ear, nose and throat) — for suspected enlarged tonsils or adenoids, chronic congestion, or suspected sleep apnea. Adenoids can't be seen by looking in the mouth, so this usually needs a specialist.

A speech-language pathologist — for oral motor difficulty, swallowing, tongue tie effects, and myofunctional concerns. Where eating and drinking are part of the picture, see feeding therapy.

An occupational therapist — where sensory awareness of saliva or oral sensory differences are part of the picture.

A sleep specialist — where obstructive sleep apnea is suspected. A sleep study is the definitive assessment.

What happens at the appointment?

Expect questions before tests. The doctor asks when the drooling started, whether it happens awake or only asleep, and about snoring, feeding and development, then examines the mouth, nose and throat; MedlinePlus describes the assessment as a physical examination with questions about symptoms and history.⁠¹⁰ Where swallowing is in question, a speech-language pathologist can assess whether saliva or food is going down the wrong way.⁠¹⁰ If your child snores and has other signs of sleep apnea, the American Academy of Pediatrics guideline recommends a sleep study, or other tests or a specialist referral where a sleep study is not available.⁠⁴ The notes and the phone recording suggested below answer questions a single visit cannot.

Find a speech-language pathologist or occupational therapist near you.

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Browse the DrSensory Therapy Directory →

What can you do at home about drooling in sleep?

Supportive, not a substitute for assessment.

Treat congestion. If allergies or a blocked nose are the cause, addressing that often resolves the drooling. Discuss with your doctor.
Try side or back positioning if your child sleeps face-down. For a baby under one, back only: see safe sleep for a drooling baby.
Keep the bedroom air comfortable. Dry air worsens congestion.
Protect the skin. Change a damp pillowcase and dry the chin in the morning, and watch for skin breakdown around the lips and chin.⁠¹⁰
Protect the mattress, and let it be a non-issue. Children made to feel embarrassed about drooling don't stop drooling. They just feel worse about it.
Note the pattern — which nights, which positions, whether snoring accompanies it. Useful at the appointment.
Record the sound if there's snoring or you've noticed breathing pauses. A phone recording of a child's night breathing is genuinely useful to a clinician and hard to describe otherwise.

Why shouldn't you tape a child's mouth closed at night?

Mouth taping circulates online as a remedy for mouth breathing and isn't appropriate for children. If a child breathes through their mouth because they can't breathe comfortably through their nose, closing the mouth doesn't address the obstruction — it needs assessing. A 2025 systematic review found only ten studies, with 213 patients in all: two showed an improvement in sleep apnea measures, the others found no difference, and some discussed risks including asphyxiation when the nose is blocked. Many of the studies excluded anyone with nasal obstruction, which is often the reason a child mouth breathes in the first place.⁠¹⁴,⁠¹⁵

Frequently Asked Questions

When is drooling a red flag?

Sudden onset in a child who was not drooling before, drooling on only one side, difficulty swallowing or choking during meals, loss of previously acquired skills, or observed pauses in breathing during sleep. Any of these warrants prompt medical attention.

At what age should a child stop drooling?

Most children largely stop daytime drooling between two and four years old. Occasional nighttime drooling stays common at any age, including in adults. Persistent drooling past four is worth mentioning to a doctor or dentist.⁠⁷

Does drooling mean my child has sleep apnea?

Not on its own. Drooling usually means mouth breathing, which has many causes including a simple blocked nose. Sleep apnea is more likely if there is also loud snoring most nights, pauses in breathing, gasping, restless sleep, or daytime sleepiness. Mention those specifically to your doctor.

Should I tape my child's mouth shut at night?

No. Mouth taping circulates online as a remedy and is not appropriate for children. If a child is mouth breathing because they cannot breathe comfortably through their nose, the obstruction needs assessing. Closing the mouth does not address it.⁠¹⁴

Is it normal for kids to drool in their sleep?

Occasional nighttime drooling is common and usually harmless — it happens when the mouth falls open and swallowing slows during deep sleep. It is worth checking if it persists past around age four, or comes with snoring, mouth breathing, or breathing pauses.

Why does my child drool at night but not during the day?

Swallowing slows during sleep and the mouth is more likely to fall open, particularly when sleeping on the side or front. If it happens most nights, the usual reason is that your child is breathing through their mouth while asleep.

Can mouth breathing affect my child's teeth or face shape?

Long-term mouth breathing has been associated with changes in palate and facial development and with a higher rate of dental problems. One proposed explanation is that resting tongue position affects how the upper jaw grows, though a direct causal link is not established and factors like genetics and allergies also contribute. A pediatric dentist can assess this.⁠⁵,⁠¹⁷

Could my child's attention problems be caused by poor sleep?

Poor sleep can produce irritability, hyperactivity, and difficulty concentrating in children, which overlaps with ADHD. That does not mean attention difficulties are usually a sleep problem — but if your child snores or mouth breathes, mention it during any assessment. It is relevant information a clinician may not think to ask for.

Is drooling in sleep a sign of teething?

It can be. The American Academy of Pediatrics lists drooling among the occasional symptoms of teething, along with mild irritability, a low-grade fever and an urge to chew on something hard.⁠¹¹ Teething does not explain drooling that continues past age 4, which is considered abnormal,⁠⁷ or drooling that comes with snoring or pauses in breathing.

Can I put my drooling baby to sleep on their side?

No. A baby under one sleeps on their back for every nap and every night, whatever the drool. The American Academy of Pediatrics describes the side position as just as dangerous as the stomach position, partly because a baby can roll from it onto the stomach.⁠¹³ Wipe the drool, change a damp sheet, and keep the sleep space firm, flat and clear.

Should I use a teething necklace to help with drooling?

No. The FDA has received reports of deaths and serious injuries in infants and children, including strangulation and choking, caused by teething jewelry such as amber teething necklaces. For sore gums, the FDA suggests gently rubbing them with a finger or offering a firm rubber teether that is not liquid-filled.⁠¹¹

Can allergies make my child drool at night?

Yes, indirectly. Allergies and sinus infections are among the recognized causes of drooling,⁠¹⁰ usually because a blocked nose leaves a child breathing through the mouth during sleep. If the drooling comes and goes with congestion or with the seasons, treating the congestion with your doctor's advice is the place to start.

Does sudden drooling mean my child is sick?

It can. Throat and mouth infections such as strep throat, tonsillitis, mononucleosis and a peritonsillar abscess are among the causes of drooling. MedlinePlus advises contacting the doctor if a child who is drooling has a fever, has difficulty breathing or holds their head in an unusual position, or if there is any worry about choking.⁠¹⁰

Can medicines cause drooling in sleep?

Yes. Drooling is a recognized side effect of some medicines,⁠⁷,⁠¹⁰ so a new pattern of drooling that began after a medicine was started is worth mentioning to the doctor who prescribed it. Do not stop a medicine or change a dose without medical advice.

Medical disclaimer. This page is for general educational purposes and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your child. If your child's drooling started suddenly, affects one side, comes with difficulty swallowing, or you've noticed pauses in their breathing during sleep, contact their doctor promptly.

Drooling in Sleep in Babies and Kids: What's Normal at Each Age