Why is my child mouth breathing?

This article was first published in July 2025 and last updated April 5, 2026.

Mouth breathing in children is often caused by allergies, congestion, or enlarged tonsils/adenoids. While occasional mouth breathing is common, persistent symptoms—especially during sleep—can affect your child’s health, sleep quality, and development. A pediatric ENT specialist can help determine the cause and best treatment.

If you've seen your child sleeping with their mouth open night after night, or even breathing through their mouth during the day, you might be wondering: Is this normal? Should I be worried?

Connecticut Children's pediatric ENT MDs, Katherine Kavanagh and Amy Hughes, take a closer look at mouth breathing in kids.
 

Why is my child breathing through their mouth?

Mouth breathing means your child is regularly breathing through their mouth instead of their nose. This can happen because of:

  • Nasal congestion from colds, allergies, or sinus infections
  • Enlarged tonsils or adenoids that block airflow through the nose
  • Deviated septum or other structural issues in the nose
  • Breathing a certain way out of habit, especially in younger kids

While many of these causes come and go, persistent, long-term mouth breathing can cause complications if not addressed by a doctor.

When should I worry about mouth breathing in my child? 

Here are some signs it’s time to see a doctor: 

  • Snoring or noisy breathing during sleep
  • Sleepiness, crankiness or trouble focusing during the day
  • Speech or swallowing difficulties
  • Changes in facial growth or dental alignment (such as long face or open bite)

If you're noticing any of the above, it's a good idea to ask your pediatrician for a referral to an ENT.  The good news: with the right evaluation and care plan, many of this can be reversed—or prevented in the first place.

When should parents NOT worry about mouth breathing?

  • Mouth breathing that happens only at night
  • Mouth breathing at night that is NOT associated with snoring or sleep concerns
     

 

Would you like to schedule an appointment for Ear, Nose and Throat (ENT) care?

quote icon

With the right evaluation and care plan, many [mouth breathing issues] can be reversed—or prevented in the first place.

Katherine Kavanagh, Pediatric ENT,
Connecticut Children's

How can a pediatric ENT help with mouth breathing?

At Connecticut Children’s, our Ear, Nose and Throat (ENT) specialists are experts in identifying whether there is an underlying cause of mouth breathing in kids. Here's how we help:

  • Complete ENT evaluation: Including nasal and throat exam, medical history, and symptom review
  • Imaging or sleep studies: If we suspect enlarged tonsils, adenoids, or sleep apnea, we may recommend a sleep study.

Treatment options for mouth breathing may include:

  • Nasal sprays or allergy management
  • Surgery (if needed) for enlarged tonsils or adenoids

We work closely with families to find the best treatment for each individual child.

What to expect at your child’s ENT visit

Not sure what happens at an ENT appointment at Connecticut Children’s? Here’s what most families experience:

  • Questions about sleep, snoring, behavior, and allergies
  • An exam of your child’s ears, nose, mouth, and throat
  • The doctor may use a small, flexible camera to gently look inside your child’s nose. This helps them see the nasal passages and possibly the adenoids at the back of the nose
  • A collaborative care plan, tailored to your child’s needs

Time to ask all your questions—because your peace of mind matters!
 

Want more articles like this from pediatric experts you trust?

Sign up for our newsletter.

Frequently Asked Questions

This is often due to nasal congestion, allergies, or enlarged tonsils/adenoids that make it harder to breathe through the nose.

Yes. Ongoing mouth breathing may impact sleep quality, behavior, dental development, and overall health.

If it happens regularly—especially during sleep—or is paired with snoring, poor sleep, or daytime fatigue, it’s worth discussing with a pediatrician.

Treatment depends on the cause and may include managing allergies, treating infections, or evaluating tonsils and adenoids.