Not all noisy breathing in children is the same — and the difference matters. A wheeze, a stridor, a rattle, a snuffle: each comes from a different part of the airway, points to a different diagnosis, and requires a different approach. Knowing which you are dealing with is the first step.
Types of noisy breathing — a parent's guide
Wheeze
A wheeze is a high-pitched, musical sound produced when breathing out. It comes from the small airways deep in the lungs and is caused by narrowing — most often from asthma, bronchiolitis (in infants), or a viral-triggered wheeze. Wheeze in a child over three is asthma until proven otherwise.
Stridor
Stridor is a harsh, high-pitched noise on breathing in. It comes from the upper airway — the larynx or trachea. In a young infant, persistent stridor that has been present since birth suggests laryngomalacia (floppy larynx) — the most common cause of noisy breathing in babies, usually benign and self-resolving by 18 months. New-onset stridor in an older child warrants prompt investigation — possible causes include croup, epiglottitis, or a foreign body.
Rattly or wet-sounding breathing
A low-pitched, rattling sound — like breathing through mucus. Usually comes from the central airways (trachea and large bronchi). Common causes include retained secretions, protracted bacterial bronchitis (PBB), or tracheomalacia (floppy trachea). If persistent, it always warrants investigation.
Stertor
A snoring, snuffling sound from the nose and throat — typically from adenoid enlargement, nasal congestion, or obesity. Often worse at night. If present during sleep, see the section on sleep apnoea.
What causes wheeze in children?
In infants (under 12 months)
- Bronchiolitis — viral infection (usually RSV) causing wheeze and respiratory distress in young infants. Very common; most cases resolve at home. Occasionally requires hospital admission.
- Tracheomalacia — floppy trachea causing a barky cough and expiratory wheeze, often worse with crying. Usually improves with age.
- Gastro-oesophageal reflux — reflux can trigger wheeze by irritating the airways.
In toddlers and pre-school children
- Viral-triggered wheeze (episodic viral wheeze) — the most common pattern. Wheeze only during viral infections, completely well between episodes. Most children outgrow this.
- Multiple-trigger wheeze — wheeze triggered by viruses, exercise, allergens, and cold air. More likely to be persistent asthma; more likely to benefit from preventer treatment.
- Foreign body inhalation — a sudden-onset wheeze in a toddler, especially if unilateral, should raise immediate suspicion of an inhaled foreign body. A peanut, bead, or coin lodged in the airway is a medical emergency. Always consider this diagnosis.
In school-age children and teenagers
- Asthma — the dominant diagnosis. See the asthma article for detail.
- Vocal cord dysfunction (VCD) — paradoxical movement of the vocal cords causing wheeze and breathlessness, particularly in adolescent girls. Frequently misdiagnosed as asthma. Does not respond to inhalers; responds to breathing techniques and speech therapy.
- Has sudden-onset wheeze or stridor (especially after eating or playing with small objects)
- Has blue lips or fingertips
- Is working very hard to breathe — nostrils flaring, ribs showing with each breath
- Cannot speak or cry normally due to breathing difficulty
What happens in clinic?
I take a careful history — the timing of the noise, whether it's on breathing in or out, what makes it better or worse, and whether there was a sudden onset. I examine the chest carefully and listen to the breathing pattern. Investigations may include:
- Spirometry and FeNO for older children (asthma assessment)
- Chest X-ray to look for hyperinflation, foreign bodies, or structural abnormality
- Flexible bronchoscopy — where I pass a thin camera into the airway under sedation, to directly visualise the larynx, trachea, and bronchi. This is the definitive investigation for unexplained stridor or persistent wheeze.
- CT chest for structural airway abnormalities
