A newborn who keeps breathing through the mouth is usually telling you something about the nose. In most cases the reason is an ordinary stuffy nose that home care can ease, and serious causes are the exception. But the same habit can also be the first visible clue to a blockage that needs a doctor, which is why the details around it matter more than the open mouth itself.
Why Newborns Are Meant to Breathe Through the Nose
Newborns depend on the nose for air.1PubMed Central. It Takes a Mouth to Eat and a Nose to Breathe: Abnormal Oral Respiration Affects Neonates’ Oral Competence and Systemic Adaptation The reflex to switch smoothly to mouth breathing usually doesn’t develop until about 3 to 4 months. So a young baby with a blocked nose has fewer backup options than an older child.
Feeding is usually where a blocked nose shows up first. A feeding baby has the mouth sealed around a nipple or bottle, so the nose is the only airway left during each suck. When it’s blocked, a baby may pull off to gasp, then fuss and root to latch again, which can look like refusing the feed. Parents often notice this pattern of starting, pulling off, and crying before they notice any open-mouth breathing.
Regular mouth breathing during sleep often points to some blockage in the nose or throat. A mouth that falls open briefly while your baby drifts off, with quiet, easy breathing, is a different thing. Babies who breathe comfortably through the nose tend to rest with lips closed and the tongue up against the roof of the mouth.2CoDAS. Association between tongue, lips position and breathing in newborns Babies with uneven or poor airflow through one nostril more often rest with lips open and the tongue low.3CoDAS. Association between tongue, lips position and breathing in newborns
To check, watch during calm sleep rather than crying, since crying babies always open their mouths. Look at whether the lips stay parted for long stretches with air moving in and out. Listen for whistling, snorting, or snuffling that suggests a partly blocked nose. And notice whether feeds are interrupted by pulling off the breast or bottle to gasp.
The Most Common Causes Are a Stuffy Nose
Many newborns sound congested in the first days because some fluid from birth remains in the nose.4Kids2Shop. When To Worry About Newborn Congestion: Crucial Signs It typically settles on its own within days. A cold looks different: runny mucus, sneezing, and sometimes a fever or fussiness. Older siblings or visitors with colds make a cold more likely. Any fever in a baby under 3 months needs a call to the doctor.
Colds are a frequent cause of a stuffy nose in babies of any age. A newborn’s nasal passages are tiny, so even a small amount of mucus or swelling narrows them a lot. Babies can’t blow their noses, so mucus stays put until it is cleared, drains, or is suctioned. A cold that gives an adult a mild sniffle can make a baby sound loud and rattly.
Dry indoor air, especially in winter with the heating on, is one of the most common ongoing causes of newborn stuffiness.5Kids2Shop. When To Worry About Newborn Congestion: Crucial Signs A cool-mist humidifier can add moisture to the room. Clean it regularly so it doesn’t spread mold.
Smoke in the home makes noses swell. Smoke on clothes, in the car, or indoors is worth ruling out for a baby with a stuffy nose.6PubMed. Thirty minute-exposure to aged cigarette smoke increases nasal congestion in nonsmokers7PubMed Central. The Relationship Between Personal Factors, Smoke Exposure at Home, and Respiratory Problems in Early Childhood in Nakhon Si Thammarat Province, Thailand Smoke clings to clothing, hair, and upholstery, so someone who smokes outside can still bring it to the baby on their clothes. Changing clothes and washing hands before holding the baby cuts down on this, but quitting is the only complete fix. Opening a window or smoking in another room doesn’t remove smoke from the air the baby breathes. Keep the home and car completely smoke-free, including vaping.
Reflux is an often-missed cause. Stomach contents coming back up can irritate the back of a baby’s nose and cause a lasting blockage.8PubMed. Consultation with the Specialist: Diagnosis and Management of the Newborn and Young Infant Who Have Nasal Obstruction A baby who spits up often and always seems stuffy without a cold may be worth asking a doctor about.
How to Clear Your Baby’s Nose at Home
Rinsing a baby’s nose with saline drops or spray (salt water made for the nose) is a sensible treatment for infant stuffiness.9PubMed Central. Nasal Irrigations: A 360-Degree View in Clinical Practice Use it whenever you notice your baby struggling to breathe through the nose, because clearing the nose can improve both sleep and feeding.10PubMed Central. Nasal Irrigations: A 360-Degree View in Clinical Practice11PubMed. Efficacy and safety of seawater-based nasal irrigation on nasal congestion in infants and toddlers with common cold: a randomized controlled trial12PubMed. Efficacy and safety of seawater-based nasal irrigation on nasal congestion in infants and toddlers with common cold: a randomized controlled trial
Choose plain saline made for babies, with only salt and water. Avoid medicated nasal sprays unless a doctor has prescribed them. Drops are easier to control than a spray for a very young baby, and the dose is simple: a couple of drops per nostril.
Gentle suction works alongside the drops, since it can reduce how hard a congested baby works to breathe.13PubMed Central. Nasal Irrigations: A 360-Degree View in Clinical Practice A few salt-water drops followed by a bulb or nasal aspirator is a common routine. There’s no agreed best frequency, so use it when needed, especially before feeds and sleep. If your baby is breathing comfortably and feeding well, there’s no need to clear the nose just because it sounds a bit noisy.
Lay your baby on the back with the head slightly tilted. Put two or three drops in each nostril and wait about a minute. Squeeze the bulb first, place the tip gently at the nostril, then release. Afterward, wipe the baby’s nose and wash the bulb in warm soapy water.
Suctioning too often can irritate the nose and make swelling worse, and pushing the tip deep into the nose can cause injury. Medicated decongestant drops and cold medicines are not for newborns.
If your baby fights the suction, swaddle the arms or have a second adult hold the head steady so the tip stays still. Try it when the baby is calm, not after hunger has set in and crying has started. Crying itself makes the nose lining swell and run, so keep sessions short and stop if your baby is very upset. And if drops and suction don’t bring clear relief, the cause may be more than ordinary mucus, so mention it to the doctor.
Warning Signs That Need Urgent Help
Call emergency services for any of these signs:
- Blue or gray lips, fingertips, or skin around the mouth.14Blueberry Pediatrics. Why Does My Newborn Sleep With Their Mouth Open? A Pediatrician’s Guide
- Skin pulling in between the ribs, above the collarbone, or below the breastbone with every breath, called retractions.15Blueberry Pediatrics. Why Does My Newborn Sleep With Their Mouth Open? A Pediatrician’s Guide
- A repeated grunt at the end of each breath out, which is the body trying to keep the airway open.16Blueberry Pediatrics. Why Does My Newborn Sleep With Their Mouth Open? A Pediatrician’s Guide
- Turning blue during feeds, which can signal a blocked nose that leaves no other way to breathe.17PubMed Central. Clinical retrospective analysis of 15 cases of choanal atresia – Our experience
These are signs of real breathing distress needing 911 or the nearest emergency department without waiting.18Blueberry Pediatrics. Why Does My Newborn Sleep With Their Mouth Open? A Pediatrician’s Guide A video visit isn’t the right route. A fever in any baby under 3 months also needs prompt medical attention.
While you wait for help, call first, then stay with the baby and keep the baby in the position where breathing looks easiest, usually held upright or on the back. Don’t give anything by mouth, since a struggling baby could choke. If you can, tell the dispatcher your baby’s age and exactly what you’re seeing, because that determines how fast help is sent.
Some signs call for a doctor’s visit in the next day or two instead: high-pitched noisy breathing when breathing in, feeds that take much longer or end early because the baby can’t breathe, fewer wet diapers than usual, or stuffiness or mouth breathing that lasts beyond a couple of weeks or happens only on one side.
It helps to tell the doctor when the mouth breathing started and whether it’s constant or only in sleep. Mention any snoring, pauses in breathing, or noisy breaths. Describe how feeding, spit-up, and wet diapers are going, and any smoke exposure or sick contacts at home.
Structural and Medical Causes Doctors Look For
In choanal atresia, the opening at the back of the nose is closed off, on one side or both. When both sides are closed it’s life-threatening right after birth, because the baby cannot breathe through the nose.19PubMed Central. Clinical retrospective analysis of 15 cases of choanal atresia – Our experience It may show as turning blue while feeding, because the tongue blocks the mouth too.20PubMed Central. Clinical retrospective analysis of 15 cases of choanal atresia – Our experience Doctors first check by trying to pass a thin tube through each nostril.21Arquivos Internacionais de Otorrinolaringologia. Nasal Obstruction of the Newborn: a Differential Diagnosis They then keep the mouth open with a special device and call a nose and throat specialist to look with a small camera.22Arquivos Internacionais de Otorrinolaringologia. Nasal Obstruction of the Newborn: a Differential Diagnosis
The middle wall of the nose can also be bent by pressure in the womb or during a difficult delivery.23PubMed. Neonatal nasal septal deviation: Two cases of successful early surgical intervention It is more common in first babies, emergency C-sections, and heavier babies.24PubMed Central. Prevalence of Nasal Septal Deviation in New-borns and Its Precipitating Factors: A Cross-Sectional Study Some cases can be corrected early with surgery.25PubMed. Neonatal nasal septal deviation: Two cases of successful early surgical intervention
In laryngomalacia, soft tissue above the voice box flops inward with each breath in, causing a high-pitched noise.26PubMed Central. Laryngomalacia: Disease Presentation, Spectrum, and Management It is the most common cause of noisy breathing in newborns.27PubMed Central. Laryngomalacia: Disease Presentation, Spectrum, and Management The extra effort of breathing can push stomach acid up, adding reflux to the picture.28PubMed Central. Laryngomalacia: Disease Presentation, Spectrum, and Management The noise typically starts in the first weeks and often gets louder when the baby is crying, feeding, or lying on the back. Most babies with it feed and grow normally, so the noise is more worrying to parents than to the baby. Feeding trouble, choking, or poor weight gain alongside the noise should prompt a closer look.
These problems don’t behave like a cold. A one-sided blockage often causes stuffiness and discharge on only one side, and structural problems persist rather than coming and going with colds. Most are found by a doctor’s exam, not at home.
A baby with one side blocked may still breathe comfortably, so the problem can go unnoticed for weeks. Gently closing one nostril at a time while the baby is calm can show whether air moves easily on both sides, though this is only a rough check. Persistent discharge from one side, with no cold symptoms, is a reason to ask the doctor to look.
What happens next depends on the cause. Many floppy voice box cases improve as the baby grows. The doctor may refer you to an ear, nose and throat specialist, and severe cases with feeding or weight problems may need treatment.
Does Mouth Breathing Affect Sleep and Growth
In the short term, the effects show up in sleep and feeding. Babies with more frequent airway blockage during sleep got less dream sleep,29Oxford Academic (Sleep). Sleep-disordered breathing and its effects on sleep in infants so breathing trouble at night can disrupt a baby’s sleep. A baby with a blocked nose may also feed poorly until it clears.30PubMed Central. It Takes a Mouth to Eat and a Nose to Breathe: Abnormal Oral Respiration Affects Neonates’ Oral Competence and Systemic Adaptation
Over a longer span, mouth breathing that continues into childhood is linked to a narrower upper jaw and a high, arched palate.31PubMed Central. Mouth Breathing and Craniofacial Development in Children: A Systematic Narrative Review and Clinical Implications It is also linked to bite problems such as an open bite and a crossbite.32PubMed Central. Mouth Breathing and Craniofacial Development in Children: A Systematic Narrative Review and Clinical Implications Mouth-breathing children tend to have a longer face and a narrower airway at the throat.33PubMed Central. Effects of mouth breathing on facial skeletal development in children: a systematic review and meta-analysis
These findings come from older children whose mouth breathing continued for years, not weeks. A cold that lasts days or a stuffy nose from dry air won’t change how a baby’s face grows. Facial growth is shaped by many things, including genetics, so mouth breathing is only one possible contributor.
If mouth breathing continues after infancy, talk with the pediatrician, who can look for causes such as enlarged tonsils or adenoids or allergies. Loud snoring, restless sleep, or pauses in breathing are worth describing, since they point toward a blockage that needs evaluation. A dentist or orthodontist may also notice jaw changes later.