Wheezing in Babies & Toddlers

Content reviewed against published AAP, NHLBI, AAP guidelines

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Wheezing is a high-pitched whistling sound heard during breathing, usually on exhalation (breathing out). It occurs when airways are narrowed by swelling, mucus, or constriction. In infants, bronchiolitis (often caused by RSV) is the most common cause. In toddlers, recurrent wheezing may indicate asthma. Wheezing is different from congestion or noisy upper airway breathing.

Key takeaways

  • Wheezing is a high-pitched whistling sound heard during breathing, usually on exhalation (breathing out).
  • Most common cause: Bronchiolitis (RSV or other viral)
  • Emergency: Wheezing with blue or gray lips/fingernails
  • Home care: Keep baby upright or with head slightly elevated

Possible Causes

Bronchiolitis (RSV or other viral)common
Viral-induced wheeze (with colds)common
Asthma or reactive airway diseasecommon
Allergic reactionuncommon
Foreign body aspirationuncommon
Pneumoniauncommon
Tracheomalacia or bronchomalacia (floppy airway)uncommon
Cystic fibrosisrare

When to Seek Help

Emergency — Call 911 or go to ER:

  • Wheezing with blue or gray lips/fingernails
  • Severe breathing difficulty — cannot cry, talk, or feed
  • Sudden onset wheezing with choking (possible foreign body)
  • Silent chest — previously wheezing but now no air movement heard
  • Baby is limp or losing consciousness
  • Severe allergic reaction with wheezing and facial swelling

Urgent — See doctor today:

  • First episode of wheezing in a baby under 6 months
  • Wheezing with significant chest retractions
  • Wheezing not improving with prescribed rescue inhaler after 20 minutes
  • Wheezing with inability to feed or drink
  • Wheezing with fever above 104°F (40°C)

Same-day appointment:

  • Recurrent wheezing with cold needing new or refill prescription
  • Mild wheezing responding to inhaler but returning within 4 hours
  • Wheezing with moderate cold symptoms and baby still feeding reasonably

Monitor at home:

  • Very mild end-expiratory wheeze at the tail end of a cold with baby feeding and playing normally
  • Known asthma with mild wheezing responding to treatment plan
  • Brief wheezing episode that resolved completely on its own

By Age

0-6 months

Normal: Some noisy breathing from nasal congestion or small airways is common and is NOT true wheezing. True wheezing (expiratory whistling from the chest) at this age usually indicates bronchiolitis.

Worry if: True wheezing (whistling from chest) in a baby under 6 months, especially with fast breathing, poor feeding, or chest retractions. Premature babies are at higher risk for severe illness.

6-12 months

Normal: First episodes of viral-induced wheeze are common at this age as babies encounter their first respiratory viruses. Mild wheezing with normal feeding may resolve on its own.

Worry if: Wheezing with respiratory distress (fast breathing, retractions, nasal flaring), poor feeding, or worsening over hours rather than improving.

1-3 years

Normal: Recurrent wheezing with viral colds is common in toddlers. Many children wheeze with infections and do not develop asthma.

Worry if: Sudden onset wheezing without cold symptoms (possible foreign body or allergic reaction), wheezing not responding to prescribed inhaler, wheezing with inability to speak or drink.

Any age

Normal: Mild wheezing at the end of a cold that resolves on its own within a few days.

Worry if: Wheezing combined with: blue lips, severe difficulty breathing, baby becomes silent (may indicate airways are too tight to make sound), or progressive worsening.

Home Care

  • Keep baby upright or with head slightly elevated
  • Run a cool-mist humidifier in the room
  • Use nasal saline drops and gentle suctioning to clear congestion
  • Offer frequent small feeds to maintain hydration
  • If prescribed, use rescue inhaler (albuterol) with spacer and mask as directed
  • Keep baby away from cigarette smoke, strong perfumes, and other irritants
  • Monitor breathing rate and watch for worsening signs
  • Do NOT give cough suppressants or decongestants to babies

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Frequently asked questions

What causes wheezing?
Bronchiolitis (RSV or other viral) (common); Viral-induced wheeze (with colds) (common); Asthma or reactive airway disease (common); Allergic reaction (uncommon); Foreign body aspiration (uncommon); Pneumonia (uncommon); Tracheomalacia or bronchomalacia (floppy airway) (uncommon); Cystic fibrosis (rare)
When is this an emergency?
Wheezing with blue or gray lips/fingernails. Severe breathing difficulty — cannot cry, talk, or feed. Sudden onset wheezing with choking (possible foreign body). Silent chest — previously wheezing but now no air movement heard. Baby is limp or losing consciousness. Severe allergic reaction with wheezing and facial swelling
What can I do at home?
Keep baby upright or with head slightly elevated. Run a cool-mist humidifier in the room. Use nasal saline drops and gentle suctioning to clear congestion. Offer frequent small feeds to maintain hydration. If prescribed, use rescue inhaler (albuterol) with spacer and mask as directed. Keep baby away from cigarette smoke, strong perfumes, and other irritants. Monitor breathing rate and watch for worsening signs. Do NOT give cough suppressants or decongestants to babies
When should I call the doctor?
Recurrent wheezing with cold needing new or refill prescription. Mild wheezing responding to inhaler but returning within 4 hours. Wheezing with moderate cold symptoms and baby still feeding reasonably

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 wheezing in babies are not emergencies. However, seek immediate care if wheezing with blue or gray lips/fingernails.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.