Mouth Breathing in Babies & Toddlers
Content reviewed against published AAP, NIH, AAP guidelines
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Newborns are obligate nasal breathers for the first several months of life, meaning they breathe primarily through their nose. Mouth breathing in a young infant is unusual and may indicate nasal obstruction. In older babies and toddlers, temporary mouth breathing during colds is common and expected. However, chronic mouth breathing (habitually breathing through the mouth when not congested) can indicate enlarged adenoids, allergic rhinitis, or other nasal obstruction and may affect facial development, dental alignment, and sleep quality if left unaddressed long-term.
Key takeaways
- Newborns are obligate nasal breathers for the first several months of life, meaning they breathe primarily through their nose.
- Most common cause: Nasal congestion from viral illness (temporary)
- Emergency: Newborn unable to breathe through nose and in distress (possible bilateral choanal atresia)
- Home care: Use saline nasal drops and gentle bulb suction to clear nasal congestion
Possible Causes
When to Seek Help
Emergency — Call 911 or go to ER:
- Newborn unable to breathe through nose and in distress (possible bilateral choanal atresia)
- Mouth breathing with severe respiratory distress, cyanosis, or inability to feed
Urgent — See doctor today:
- Infant unable to breastfeed due to nasal obstruction not clearing with saline
- Sudden onset mouth breathing with unilateral foul nasal discharge (foreign body)
Same-day appointment:
- Chronic mouth breathing with daytime sleepiness and loud snoring (sleep apnea evaluation)
- Mouth breathing with documented poor growth or failure to thrive
- Mouth breathing with suspected foreign body in nose
Monitor at home:
- Temporary mouth breathing during a cold that resolves within 1-2 weeks
- Mild mouth breathing during sleep only with no snoring or apnea
- Occasional open-mouth posture in a toddler learning to breathe through congestion
By Age
0-3 months
Normal: Young infants should breathe through their nose. Temporary mouth breathing during vigorous crying is normal.
Worry if: Persistent mouth breathing in a newborn (may indicate choanal atresia or severe nasal obstruction). Inability to breathe while feeding (babies cannot nurse and mouth breathe simultaneously). Mouth breathing with retractions or distress.
3-12 months
Normal: Mouth breathing during colds is common as nasal passages become congested. Should resolve as congestion clears.
Worry if: Chronic mouth breathing when not sick. Mouth breathing interfering with feeding. Mouth breathing with snoring and observed apnea during sleep.
1-3 years
Normal: Temporary mouth breathing during upper respiratory infections is expected and common given frequency of illness in this age group.
Worry if: Habitual open-mouth posture when awake and not congested. Chronic mouth breathing with snoring, bad breath, dry lips, or dental problems. Mouth breathing with "adenoid facies" (long face, open mouth, high palate). Mouth breathing with speech abnormalities or feeding difficulties.
Home Care
- Use saline nasal drops and gentle bulb suction to clear nasal congestion
- Run a cool-mist humidifier in the bedroom, especially during dry seasons
- Elevate head of mattress slightly for babies with congestion
- For allergic rhinitis: reduce allergen exposure (dust, pet dander, pollen)
- Keep nasal passages moisturized with saline spray in dry climates
- Encourage nose breathing during awake time (gentle reminders for older toddlers)
- For young infants: saline drops before feeds to clear nasal passages and allow nursing
- Avoid cigarette smoke and strong irritants that cause nasal swelling
- If chronic mouth breathing persists when well, consult pediatrician about adenoid evaluation
- Do NOT use over-the-counter decongestant sprays in children under 6 years
Frequently asked questions
What causes mouth breathing?
When is this an emergency?
What can I do at home?
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Sources
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources
Related Symptoms
Bottom line
Most cases of mouth breathing in babies are not emergencies. However, seek immediate care if newborn unable to breathe through nose and in distress (possible bilateral choanal atresia).
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.