You lean over the crib and see your baby’s lips parted, with air moving through the mouth instead of the nose.
It is a common sight, and it often brings a quick worry about whether something is wrong.
So, can babies breathe through their mouth? Yes, they can, but in the first months of life they strongly prefer the nose, so mouth breathing usually means the nose is blocked by mucus, a cold or, less often, a structural problem.
In this post, you will learn why infants favour nose breathing, what causes mouth breathing, how to ease a stuffy nose safely, and which breathing signs mean you should call your paediatrician or 911.
Can Babies Breathe Through Their Mouth?
Yes, babies can breathe through their mouth, including newborns, but they are preferential nose breathers.
Their anatomy sends air through the nose by default, which lets them breathe and feed at the same time.
When the nose is blocked, most infants switch to the mouth after a short delay, and younger babies tend to be slower to do so.
For years, many textbooks described newborns as obligate nose breathers, meaning they could only breathe through the nose.
A 1985 study in the American Review of Respiratory Disease (Rodenstein and colleagues) tested this in 19 infants aged 1 to 230 days and found that every baby began mouth breathing once the nose was blocked.
The switch took 7.8 seconds on average and up to 32 seconds, and older or awake babies made it faster than younger or sleeping ones.
That delay explains why the youngest babies have the hardest time with a stuffy nose, which brings us to newborns.
Can Newborns Breathe Through Their Mouth?
Newborns can breathe through the mouth, but it does not come as easily as it will later in infancy.
Researchers describe the soft palate resting against the tongue in young infants, which closes off the mouth and sends air through the nose.
This setup lets a baby suck, swallow and breathe in a steady rhythm during feeds, so a blocked nose shows up quickly as feeding trouble.
You may notice your newborn pulling off the breast or bottle, fussing mid-feed or sounding snuffly.
Because young infants depend on a clear nose to breathe while they suck, keeping the nose clear matters most in the early weeks and during cold season.
The same preference for nose breathing also shapes what you see at night.
Baby Sleeping With Mouth Open: Is It Normal?
A baby sleeping with their mouth open is often normal, especially when breathing is quiet and even.
It deserves a closer look when it comes with loud snoring, pauses in breathing, restless sleep or daytime tiredness that a cold does not explain.
In those cases, your paediatrician can check whether something is narrowing the airway.
Paediatric ENT doctors at Connecticut Children’s note that open-mouth breathing at night, without snoring or other sleep concerns, is usually not a reason to worry.
They suggest asking your paediatrician about an ENT referral if your child snores, breathes noisily during sleep, sleeps poorly or seems tired during the day.
Whatever you notice, keep following AAP safe sleep guidance for the first year, which means placing your baby on their back on a firm, flat surface with nothing else in the sleep space.
With safe sleep in place, the next question is what makes the nose stop working well in the first place.
Why Is My Baby Breathing Through Their Mouth?
Most mouth breathing in babies comes from something blocking the nose. The cause can range from a passing cold to a structural problem that needs a doctor’s exam.
1. Stuffy or Blocked Nose
The AAP notes that cold, dry winter air can make nasal mucus thicker, which narrows a baby’s small nasal passages.
When enough air cannot get through the nose, your baby will open the mouth to breathe.
2. Colds and Respiratory Infections
Colds are the most common trigger, because the extra mucus they cause makes nose breathing harder work.
The AAP advises calling your paediatrician if cold symptoms are not improving each day or have not cleared after about a week.
If a fever comes along with the congestion, our guide on urgent care for fever can help you decide on next steps.
3. Enlarged Adenoids and Other Airway Problems
Adenoids are small pads of tissue high in the back of the nose, and enlarged adenoids or tonsils can partly block airflow and lead to steady mouth breathing.
A deviated septum, where the wall between the nostrils sits off centre, can also narrow one side of the nose.
Rarely, a baby is born with choanal atresia, a blockage at the back of the nasal passage.
A case report published through the National Institutes of Health notes that when both sides are blocked, a baby cannot feed and breathe at the same time, so it needs specialist care.
These problems need a paediatrician’s exam and sometimes an ENT referral. Whatever the cause, congestion changes how your baby breathes in the moment, so let’s look at that more closely.
4. Can Babies Breathe Through Their Mouth With a Stuffy Nose?
Yes. When congestion blocks the nose, babies switch to mouth breathing, but it is less comfortable for them and gets in the way of feeding because the mouth is busy sucking.
Clearing the nose with saline and gentle suction often lets them return to easier nose breathing within minutes of a good clearing.
That discomfort is usually the main problem, rather than danger. Still, it helps to know what healthy baby breathing looks like so you can spot real trouble.
How Can You Tell if Your Baby Is Having Trouble Breathing?
Mouth breathing on its own is not an emergency, but the speed and effort of your baby’s breathing tell you a lot.
Normal Baby Breathing Patterns:
Newborns breathe about 40 to 60 times per minute, and this may slow to 30 to 40 breaths per minute during sleep, according to newborn breathing problems guidance from Stanford Medicine Children’s Health.
Short pauses of 5 to 10 seconds followed by 10 to 15 seconds of quicker breaths are called periodic breathing, and the same source describes it as normal when your baby’s colour does not change.
Count breaths for a full minute while your baby is calm, since crying or being too warm can raise the rate for a short time.
Signs of Breathing Difficulty
Call your paediatrician right away if you notice any of these signs:
- Breathing faster than 60 breaths per minute that does not slow once your baby is calm
- Nostrils flaring with each breath
- Skin pulling in at the ribs, below the breastbone or above the collarbones
- Grunting or moaning with each breath
- Persistent coughing, choking or wheezing
Signs That Need Emergency Care
Call 911 right away if your baby:
- Stops breathing for more than 20 seconds
- Turns blue around the lips, face or skin
- Is working very hard to breathe, with deep pulling-in at the ribs or grunting
Do not wait to see if these signs pass on their own. Outside of emergencies, the most common effects of mouth breathing show up at feeding time and bedtime.
How to Help a Baby Who Is Breathing Through Their Mouth
For mouth breathing caused by a cold or dry air, a few steps at home can ease your baby’s breathing.
1. Help Clear a Stuffy Nose
Saline (saltwater) drops loosen thick mucus, and a bulb syringe can then gently draw it out. The FDA notes that bulb suctioning works very well for babies younger than 1 year, while older babies often resist it.
Squeeze the bulb before you place the tip at your baby’s nostril, then release it slowly, as the AAP cold care tips describe.
A cool-mist humidifier in your baby’s room can also ease congestion, and the FDA advises against warm-mist models because they can make nasal passages swell.
2. Reduce Smoke and Other Irritants
The AAP recommends keeping your home and car free of smoke and vaping for every baby.
Clean the humidifier as often as the manufacturer advises, because the AAP warns that a dirty unit can release germs and mineral deposits into the air.
3. Avoid Unsafe Remedies
The FDA does not recommend over-the-counter cough and cold medicines for children under 2 because of serious, possibly life-threatening side effects, and manufacturers label these products “do not use in children under 4″.
You can read the full FDA cold medicine guidance for more detail.
The AAP also advises against mentholated rubs for children under 2 and honey for babies under 12 months.
For fever or pain, ask your paediatrician or pharmacist which product suits your baby’s age and weight, and if your baby swallows any medicine by accident, call Poison Control at 1-800-222-1222.
When Should You Call a Doctor About Baby Mouth Breathing?
Most mouth breathing during a cold can be managed at home, but some patterns need a professional opinion.
- Frequent or Persistent Mouth Breathing:If your baby breathes through the mouth most of the time, even without a cold, ask your paediatrician to check for a blockage such as enlarged adenoids.
- Snoring or Noisy Breathing:Regular snoring or noisy breathing during sleep can point to a narrowed airway. Paediatric ENT specialists advise asking your paediatrician about a referral when you hear it often.
- Mouth Breathing With Feeding Problems:Ongoing trouble feeding because your baby cannot breathe through the nose deserves a visit, so your paediatrician can find the cause.
Other Symptoms to Watch For
The FDA advises calling a doctor for any of these symptoms:
- A fever of 100.4°F or higher in a baby 2 months or younger
- A fever of 102°F or higher at any age
- Wheezing, fast breathing or nostrils widening with each breath
- Not eating or drinking, with fewer wet diapers
- Unusual crankiness or sleepiness
- Symptoms that keep getting worse
Key Points on Baby Mouth Breathing
Since it stands clearly evident that it is common for babies to breathe through their mouth.
However, it is worth noting that their bodies are set up to breathe through the nose first, especially in the early weeks.
When you see mouth breathing, cold, dry air, or another cause of a blocked nose, it is the usual explanation, and saline, gentle suction, and a clean cool-mist humidifier are safe first steps.
Ongoing mouth breathing, regular snoring or feeding trouble without a clear cause calls for a paediatrician visit, while long pauses, blue colour or laboured breathing need emergency care.
As a next step, save the warning-sign lists above and bring any questions to your baby’s next checkup.
Frequently Asked Questions
Is It Okay to Let a Baby Sleep With a Stuffy Nose?
Yes, a mildly stuffy baby can sleep, but keep them on their back on a flat, firm surface. The AAP says even babies with reflux should sleep flat, so skip wedges or raised mattresses. Clear the nose with saline first, and call your paediatrician if breathing looks laboured.
Is It Bad if a Baby Breathes Through Their Mouth?
Occasional mouth breathing during a cold is usually not a concern on its own. Ongoing mouth breathing is a different matter because it usually means something is blocking the nose. In older children, paediatric ENT doctors say long-term mouth breathing may affect sleep quality, behaviour, and dental development.
