A baby’s cold can change surprisingly quickly. A runny nose and mild cough may seem manageable at first, then feeding becomes tiring and breathing sounds noisier. Bronchiolitis in babies is a common viral infection of the smallest airways in the lungs. Most infants recover with supportive care, but knowing what to watch for makes a real difference.
The key is not simply whether your baby wheezes. Look at how comfortably they breathe, how much milk they manage, and whether they remain alert. These clues help you decide when home care is reasonable and when medical help is needed.
What happens during bronchiolitis?
Bronchiolitis usually affects children under two, particularly during their first year. A virus inflames the tiny breathing tubes, called bronchioles, causing swelling and mucus buildup. Air then moves less easily through the lungs, producing coughing, crackling or wheezing sounds.
Respiratory syncytial virus (RSV) is the most common cause, although other respiratory viruses can also trigger infant bronchiolitis. It spreads through respiratory droplets, close contact and contaminated hands or surfaces. Bronchiolitis is not the same condition as bronchitis or asthma.
Symptoms: from an ordinary cold to a chest infection
Early bronchiolitis symptoms often include a blocked or runny nose, sneezing and a cough. A baby may have a mild fever, but fever is not always present. Over the next few days, parents may notice faster breathing, noisy breathing, fussiness or shorter feeds.
What does baby wheezing sound like?
Wheezing is a high-pitched, whistling sound, often heard as a baby breathes out. Some babies instead have a crackling sound when a clinician listens to their chest. Nasal congestion can make breathing sound noisy too, so sound alone cannot confirm bronchiolitis or establish its severity.
Watch the baby’s chest and belly while they are calm. Mildly faster breathing may accompany an infection, but persistent rapid breathing, pulling in beneath the ribs or obvious struggle demands assessment. Very young babies may show fewer typical cold symptoms and instead become unusually quiet or feed poorly.
The days when symptoms often get worse
Bronchiolitis commonly peaks around days three to five of the illness. The cough can linger for roughly three weeks even after breathing and feeding improve. Recovery is not always perfectly steady, so keep checking for changes rather than assuming the first better morning means the illness has passed.
For example, suppose your six-month-old finishes only half a usual bottle because they need frequent breathing breaks. Rather than focusing on the cough, record what they drank, count wet nappies and observe their breathing at rest. Contact a healthcare professional promptly if intake remains substantially reduced, breathing worsens or wet nappies become scarce.
Supportive treatment at home
There is no routine medicine that cures bronchiolitis. Treatment focuses on keeping babies comfortable, hydrated and breathing safely while the infection resolves. If a clinician has assessed your baby and advised home care, these measures can help:
Keep feeds manageable
Offer breast milk or formula in smaller amounts more frequently. A blocked nose and increased breathing effort can make long feeds exhausting. Pause when your baby needs a rest. For young infants, milk remains the main source of fluids; do not replace feeds with plain water.
Help with a blocked nose
Saline nasal drops and gentle suction before a feed may ease congestion. Avoid aggressive or repeated suction that irritates delicate tissues. Hold your baby comfortably upright while awake and supervised, but always place them flat on their back on a firm, clear sleep surface. Do not prop up the cot mattress or use pillows for sleep.
Check comfort and hydration
Keep your home free of cigarette smoke and check your baby regularly, including overnight. For fever or discomfort, ask a pharmacist or clinician about an age-appropriate medicine and dose. Never give aspirin to a child. Avoid over-the-counter cough and cold medicines for infants unless a clinician specifically advises them.
Antibiotics do not treat viral bronchiolitis, and inhalers such as salbutamol, steroids and nebulised treatments are not routinely recommended for typical cases. If your baby needs hospital care, clinicians may provide oxygen, fluids or feeding support, depending on their condition.
Bronchiolitis red flags: when to get help
Get emergency medical help immediately
Call your local emergency number if your baby has pauses in breathing; blue or grey lips, tongue or skin; severe difficulty breathing with grunting or deep pulling in under the ribs; or is floppy, difficult to wake or unresponsive. These are emergency signs even if the baby has no fever.
Arrange urgent medical assessment
Seek same-day medical advice if your baby is breathing faster or working harder than usual, feeding much less than normal, showing signs of dehydration, or seems increasingly unwell. No wet nappy for 12 hours is a particularly concerning sign. A baby younger than three months with a temperature of 38°C (100.4°F) or higher needs prompt medical assessment.
Trust changes you can see. If your baby’s breathing or behaviour worries you, seek help rather than waiting for the next scheduled feed or for the illness to reach its expected peak.
Which babies need extra caution?
Babies younger than three months, especially newborns, may deteriorate more quickly. Premature infants and babies with heart disease, chronic lung conditions, weakened immune systems or certain muscle and nerve conditions have a higher risk of severe illness. Their families should contact a healthcare professional early if symptoms develop.
Prevention matters too. Wash hands, clean shared surfaces, avoid close contact with people who are sick, and keep babies away from tobacco smoke. Depending on your country and eligibility, maternal RSV vaccination or infant RSV antibody protection may reduce the risk of severe RSV illness; ask your maternity or child-health provider about local options.
Frequently asked questions
Is bronchiolitis contagious?
Yes. The viruses responsible spread through droplets and contact with infected secretions. Hand hygiene and limiting close contact with sick people help reduce spread, particularly around newborns.
Does every baby with bronchiolitis wheeze?
No. Some babies mainly cough, breathe quickly or struggle with feeds. Wheezing alone is not a reliable measure of how sick a baby is.
How long should a baby stay home with bronchiolitis?
Keep your baby home while unwell and follow local childcare guidance. Return to usual activities when they are improving, feeding adequately and no longer have a fever, while continuing hygiene precautions.
Can bronchiolitis turn into pneumonia?
Bronchiolitis and pneumonia are different lower-respiratory illnesses, and occasionally an infant may develop pneumonia or another complication. A new fever, worsening breathing or persistent deterioration warrants reassessment rather than assuming it is normal recovery.
The most useful thing to monitor
Bronchiolitis in babies is often frightening because noisy breathing can appear after a relatively ordinary cold. Most recover without special treatment, but the safest home approach is active observation: note breathing effort, milk intake, wet nappies and alertness. If those measures are worsening, get medical advice. If breathing stops, becomes severely laboured or your baby is difficult to rouse, seek emergency help immediately.