The slight of a sleeping baby is probably one of the most calming things for new parents. Seeing their bundle of joy peacefully asleep reassures you that you are doing a great job; plus, you will have some time to examine those little toes and fingers, stare at their lovely little nose and sleepy eyes, loving every single tiny grunt and snore. 

In these instances, you might also notice your baby sleeping with their mouth open. And if you’ve read some information on the topic, you know that newborn mouth breathing during sleep can be a telltale sign of upper respiratory problems; these may lead to other medical complications when left unaddressed. 

Because of this, our team at Worldwide Pediatrics prepared this article to let parents learn more about why a baby might be mouth breathing during sleep and when they should inform a pediatrician about it. 

Babies Sleeping With Their Mouths Open: What Can It Mean? 

You probably know this, but babies breathe almost exclusively through their noses except for cases when their nasal passages are obstructed. Namely, newborn mouth breathing isn’t a “thing” because babies develop their reflex to breathe via their mouth later, when they are three to four months old, unless when they are crying. 

Still, experts often explain that a baby’s mouth breathing isn’t always something concerning. The condition may indeed develop as a response to a blockage in the upper airway, but the causes may often be harmless that resolve on their own, like cold, mild allergies, or a stuffy nose. 

Also, mouth breathing may be a sign of more intricate conditions. 

All in all, breathing through the mouth usually becomes a habit, and it will become harder and harder to break with age. 

Why is the Baby Sleeping with Their Mouth Open? Possible Causes 

Baby Sleeping With Mouth Open

Below are the most common potential causes of mouth breathing: 


Breathing through the mouth is necessary when the upper airways, like the nose, are blocked with mucus. This can easily happen if the baby has caught a cold or experienced a mild allergic reaction to something in their living space. 

Babies lack the motor skills and reflexes to clear the accumulated mucus without help and, therefore, may breathe via their mouth to compensate.

Deviated Septum

There are cases when the baby sleeps with its mouth open because there’s an abnormality in the bone and cartilage that should separate the nostrils. This can lead to difficulty breathing through the nose efficiently. It’s more common in people with a narrower upper jaw. 

Sleep Apnea

Mouth breathing may also be a sign of sleep apnea. This means that the newborn’s upper airways got obstructed. In young children and babies, the said obstruction is usually caused by enlarged adenoids or tonsils. 

Sleep apnea may also produce symptoms like restlessness during sleep, snoring, choking, coughing, and pauses in breathing. 


Lastly, there are also cases when the newborn starts mouth breathing out of habit following a cold and having a stuffy nose. 

What’s the Treatment When Babies Sleep With Their Mouth Open? 

Mom Massages Newborn Baby

When the baby looks like they are struggling with breathing and have other symptoms as well, it’s highly recommended that you schedule an appointment with your pediatrician. The healthcare provider can rule out any conditions that may block the airway, prescribe any medications against infections, or order testing to uncover the causes.

Apart from that, here are some of the home remedies you may try to clear any congestion: 

Use a Humidifier

The symptoms of a stuffy nose can be alleviated by adding moisture to the air. Experts recommend using cool mist humidifiers as the best option for babies and young children since they eliminate burn risks. If you don’t have one of these devices, you can also sit with your baby in the bathroom while running a hot shower to create steam. 

Use a Saline Wash

Salin water may help loosen and thin the mucus. For older babies, a neti pot or saline rinse may also help. Just make sure to use distilled or boiled and cooled tap water for safety concerns.

Use a Bulb Syringe

A bulb syringe may help suck out even small amounts of mucus from the nose. Just be gentle and ensure the syringe is clean before each use to avoid infections.

Keep the Baby Hydrated

Ensure that the baby is drinking enough breast milk or formula to keep the mucus flowing as it should. 

Again, consider reaching out to your pediatrician if a stuffy nose is no longer a problem but the baby’s still sleeping with their mouth open. Enlarged adenoids and tonsils usually don’t respond to home remedies, and a healthcare expert should evaluate them to establish the correct diagnosis and treatment. 

Medications may help with allergies; surgery might be recommended to remove the adenoids or tonsils. A deviated septum will also be treated surgically. 

Positive airway pressure therapy with BPAP and CPAP devices may help with sleep apnea. Still, keep in mind that these interventions for newborns and children are quite rare. 


Parents often disregard the problems that may arise from issues that cause mouth breathing. The truth is that the medical community has documented several problems and potential discomforts that may develop if mouth breathing isn’t addressed in the long term. 

The side effects of newborn mouth breathing may include:

  • Dry cough
  • Swollen tonsils
  • Gingivitis
  • Foul-smelling breath
  • Cavities (later on)

Also, other complications like long face syndrome may occur as well. This means that the baby’s lower facial features may elongate disproportionately, which can only be corrected surgically. 

Lastly, a baby’s mouth breathing can interfere with proper sleep and lower the blood’s oxygen concentration, leading to hypertension and heart issues over time. 

Remain Calm and Reach Out to an Expert

While a baby sleeping with an open mouth is cute, it’s better to observe with caution as sometimes the causes behind that little open mouth may point to a health condition that needs to be addressed. 

Fortunately, parents can take several steps and use several home remedies to help their baby breathe easier in the case of simple congestion. Still, if the problems persist, they should reach out to their pediatrician or dental professional and talk more about the issue. 

And when the conditions and obstructions are addressed, the baby and the parent can sleep better at night.

That said, if you’ve also noticed your baby sleeping with an open mouth lately and need some hand with home remedies or want to evaluate the situation by a professional, feel free to schedule an appointment with our expert and knowledgeable team.