Stridor (High-Pitched Breathing) in Babies & Toddlers

Content reviewed against published AAP, AAP, NIH guidelines

Editorial policy

Last reviewed:

Stridor is a high-pitched, musical breathing sound caused by turbulent airflow through a narrowed upper airway. It is most commonly heard during inspiration (breathing in) and indicates obstruction at or above the larynx (voice box). In infants, the most common cause of chronic stridor is laryngomalacia, while in toddlers acute stridor is most often caused by croup. Stridor is always an abnormal sound and warrants medical evaluation, though its urgency depends on severity, onset, and associated symptoms.

Key takeaways

  • Stridor is a high-pitched, musical breathing sound caused by turbulent airflow through a narrowed upper airway.
  • Most common cause: Croup (laryngotracheobronchitis) — acute onset in toddlers
  • Emergency: Stridor at rest with severe retractions, cyanosis, or altered consciousness
  • Home care: For croup: take child outside into cool night air for 15-20 minutes

Possible Causes

Croup (laryngotracheobronchitis) — acute onset in toddlerscommon
Laryngomalacia — chronic stridor from birthcommon
Post-extubation swelling (in NICU graduates)uncommon
Subglottic stenosisuncommon
Foreign body aspirationuncommon
Vocal cord paralysisuncommon
Hemangioma of the airwayrare
Vascular ring compressing trachearare
Epiglottitis (rare since Hib vaccine)rare
Anaphylaxis (allergic reaction with airway swelling)rare

When to Seek Help

Emergency — Call 911 or go to ER:

  • Stridor at rest with severe retractions, cyanosis, or altered consciousness
  • Sudden onset stridor suggesting foreign body aspiration or anaphylaxis
  • Stridor with drooling, high fever, and toxic appearance (possible epiglottitis or abscess)
  • Stridor with complete inability to swallow
  • Biphasic stridor (inspiratory and expiratory) with respiratory distress

Urgent — See doctor today:

  • Croup with stridor at rest (even if child is otherwise alert)
  • Stridor worsening progressively over hours despite cool air and comfort
  • Stridor with moderate retractions and agitation
  • Recurrent croup episodes (more than 2 per year) needing evaluation for underlying cause

Same-day appointment:

  • Chronic stridor with feeding difficulty or poor weight gain
  • New onset mild stridor without clear cause
  • Stridor that has changed in character from previous pattern

Monitor at home:

  • Known laryngomalacia with mild stridor, good feeding, and weight gain
  • Mild croup with barking cough but no stridor at rest
  • Intermittent stridor only during crying or agitation in known laryngomalacia

By Age

0-2 months

Normal: Intermittent mild inspiratory stridor that worsens when baby is on back or feeding and improves when calm is typical of laryngomalacia. Baby should be feeding and gaining weight well.

Worry if: Stridor at rest with retractions, stridor present from birth that is severe and constant, feeding difficulty with weight loss, or episodes of apnea or cyanosis.

2-6 months

Normal: Laryngomalacia typically worsens before improving (peaks 4-8 months). Stridor that is positional and intermittent without distress is usually benign.

Worry if: Progressive worsening stridor with failure to thrive, biphasic stridor (both in and out), associated skin hemangiomas with worsening stridor (possible airway hemangioma), or new stridor not present before.

6-12 months

Normal: Laryngomalacia should begin improving. Brief mild stridor during agitation or upper respiratory infections may occur.

Worry if: Stridor persisting or worsening beyond 12 months. Sudden onset stridor (possible foreign body). Stridor with drooling and fever.

1-3 years

Normal: Episodic stridor with croup (barking cough, worse at night) is common in this age group and usually self-limiting.

Worry if: Stridor at rest with severe retractions, inability to drink, drooling with high fever and toxic appearance, or stridor following possible choking event.

Home Care

  • For croup: take child outside into cool night air for 15-20 minutes
  • Run a hot shower and sit in the steamy bathroom (evidence is mixed but may help)
  • Keep the child calm — crying and agitation worsen stridor significantly
  • For croup: offer cold fluids if child can swallow safely
  • Use a cool-mist humidifier in the bedroom
  • Keep child upright or slightly reclined rather than flat
  • For known laryngomalacia: position on side or tummy during supervised awake time
  • Do NOT put anything in the mouth to examine the throat if epiglottitis is suspected
  • Do NOT give cough suppressants — they do not help and may mask worsening
  • Seek immediate help if child develops stridor at rest, looks blue, or becomes drowsy

Frequently asked questions

What causes stridor (high-pitched breathing)?
Croup (laryngotracheobronchitis) — acute onset in toddlers (common); Laryngomalacia — chronic stridor from birth (common); Post-extubation swelling (in NICU graduates) (uncommon); Subglottic stenosis (uncommon); Foreign body aspiration (uncommon); Vocal cord paralysis (uncommon); Hemangioma of the airway (rare); Vascular ring compressing trachea (rare); Epiglottitis (rare since Hib vaccine) (rare); Anaphylaxis (allergic reaction with airway swelling) (rare)
When is this an emergency?
Stridor at rest with severe retractions, cyanosis, or altered consciousness. Sudden onset stridor suggesting foreign body aspiration or anaphylaxis. Stridor with drooling, high fever, and toxic appearance (possible epiglottitis or abscess). Stridor with complete inability to swallow. Biphasic stridor (inspiratory and expiratory) with respiratory distress
What can I do at home?
For croup: take child outside into cool night air for 15-20 minutes. Run a hot shower and sit in the steamy bathroom (evidence is mixed but may help). Keep the child calm — crying and agitation worsen stridor significantly. For croup: offer cold fluids if child can swallow safely. Use a cool-mist humidifier in the bedroom. Keep child upright or slightly reclined rather than flat. For known laryngomalacia: position on side or tummy during supervised awake time. Do NOT put anything in the mouth to examine the throat if epiglottitis is suspected. Do NOT give cough suppressants — they do not help and may mask worsening. Seek immediate help if child develops stridor at rest, looks blue, or becomes drowsy
When should I call the doctor?
Chronic stridor with feeding difficulty or poor weight gain. New onset mild stridor without clear cause. Stridor that has changed in character from previous pattern

Sources

AAPAAPNIH

All content follows our editorial policy and is reviewed against published clinical guidelines.

2,705 evidence-based guides6 authoritative medical sources

Related Symptoms

noisy breathingdry coughgruntingblue lips

Bottom line

Most cases of stridor (high-pitched breathing) in babies are not emergencies. However, seek immediate care if stridor at rest with severe retractions, cyanosis, or altered consciousness.

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