What is bronchiolitis?

Bronchiolitis is a common chest infection caused by a virus.

Bronchiolitis causes difficulty breathing. It usually affects children under 12 months of age.

It is infectious (spreads from person to person). It is more common in autumn and winter.

What are the symptoms of bronchiolitis?

At first it will look like your baby has a winter cold. After a couple of days, they might get worse.

Symptoms include:

• a runny nose
• cough
• fever
• fast breathing
• working hard to breath
• wheeze (may be a whistling sound in chest)
• less interest in eating

Your child might find it hard to eat and drink. If your baby is not able to drink, they may become dehydrated.

Your baby might be sick for 5 to 10 days. The cough can take a few weeks to get better.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What causes bronchiolitis?

Bronchiolitis is an infection often caused by the respiratory syncytial virus (RSV). Bronchiolitis can also be caused by another virus.

The small airways in the lungs become clogged with fluid and mucus, making it hard to breathe.

If your baby was born prematurely (early), or has other health problems, they may get worse symptoms.

The virus spreads through small droplets when infected people cough, talk or sneeze.

When should I see my doctor?

Often the illness is mild, and you can look after your child at home. If you are worried that your child has bronchiolitis, take them to the doctor. It can get worse quickly.

Always take your baby to the doctor if they are:

• less than 10 weeks of age or were born early
• have a lung disease or a weakened immune system
• not eating or drinking as much as usual
• breathing very fast, wheezing or having difficulty breathing
• very tired, hard to wake or irritable
• not weeing as much as usual (less wet nappies)
• pale and sweaty
• getting worse quickly

As a guide, a baby is not eating or drinking as much as usual if they have:

• less than half of their feed for two or more feeds
• a dry nappy for 12 hours or more

When should I call an ambulance?

Dial triple zero (000) and ask for an ambulance if your child is:

• having a lot of difficulty breathing or is exhausted from trying to breathe
• turning blue

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

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How is bronchiolitis treated?

You can help your baby get better by following some tips for looking after a sick child.

• Let them have plenty of rest.
• Give them small amounts of fluids to drink frequently.
• You can use saline nasal drops to help clear their nose.
• You can give your baby paracetamol if they are unsettled and seem uncomfortable. Check the dose carefully.

Do not smoke or vape near your baby because cigarette smoke makes the symptoms worse.

Bronchiolitis symptoms can look like asthma, but it is a different condition and needs different treatment.

Antibiotics won’t work for bronchiolitis because it is caused by a virus.

If your baby needs to go into hospital, they may be given oxygen and fluid.

Can bronchiolitis be prevented?

The best ways to stop the spread of bronchiolitis are to:

• wash your hands frequently
• keep your hands away from you mouth, nose and eyes
• throw away used tissues straight away
• keep your sick baby away from other children

Resources and support

For information in other languages (Arabic, Assyrian, Burmese, Chinese – simplified, Chinese – traditional, Karen, Persian, Somali, Turkish and Vietnamese) see the Royal Children’s Hospital factsheets.

Visit Pregnancy, Birth and Baby website for more information about children's health.

You can call the healthdirect helpline on 1800 022 222. A registered nurse is available 24 hours a day, 7 days a week.