Bronchiolitis in babies: symptoms, home care and when to worry

Bronchiolitis is a chest infection that mostly affects babies under 12 months. It usually starts like an ordinary cold, then over a day or two the cough gets worse and breathing becomes faster and harder work. Most babies get better at home within 7 to 10 days with small, frequent feeds, saline nose drops and close watching. The things to keep an eye on are breathing, feeding and alertness, because those tell you when your baby needs a doctor today or an ambulance now.

What is bronchiolitis, and what causes it?

The Royal Children's Hospital Melbourne (RCH) describes bronchiolitis as a common chest infection in babies up to 12 months old. The infection makes the tiny airways in the lungs (bronchioles) swell and fill with mucus, which makes breathing and feeding harder. The NHS bronchiolitis page says it can affect children up to 2.

A range of viruses can cause it. The RCH says respiratory syncytial virus (RSV) is the most common, and the AAP's bronchiolitis guide also lists influenza, parainfluenza and human metapneumovirus. The NHS says almost all children catch RSV at least once before they're 2.

The viruses spread in droplets when people cough, sneeze or talk. The RCH explains that the same virus that gives an older sibling or adult a head cold can cause a chest infection in a baby, because a baby's lungs and immune system are more vulnerable. Australia's healthdirect says it's more common in autumn and winter.

Bronchiolitis isn't the same as a cold or croup. For a cold, see colds and congestion; for a barking cough, see croup.

What are the symptoms, and which day is worst?

It usually starts with a runny or blocked nose, a mild cough and sometimes a fever. The RCH says that after one or two days the cough tends to get worse and it gets harder for your baby to breathe. Common symptoms include:

• fast breathing
• wheezing or crackly, noisy breathing
• breathing that is hard work: the ribs or the skin under the neck sucking in, nostrils flaring, or the head bobbing in younger babies
• trouble feeding because of breathlessness, mucus and a blocked nose
• a temperature of 38°C (100.4°F) or more
• being unsettled and irritable

The sources describe a similar course, with slightly different timings:

The AAP's RSV guide says RSV symptoms are typically at their worst on days 3 to 5 and last 7 to 14 days on average. Expect your baby to get worse before they get better, and plan for a few rough nights in the middle.

Which babies are at higher risk of severe bronchiolitis?

Most babies have a mild illness, but some are more likely to need hospital help with breathing or feeding. Each source lists slightly different groups:

The Better Health Channel, run by the Victorian Government in Australia, says babies under 8 weeks should always be taken to a doctor because they are at greater risk of severe illness and dehydration. If your baby is in one of these groups and you think they have bronchiolitis, see a doctor the same day rather than waiting.

How can I care for my baby with bronchiolitis at home?

There's no medicine that cures bronchiolitis, so care at home is about keeping your baby feeding, comfortable and watched.

1. Feed small amounts more often. The RCH, Australia's healthdirect, the NHS and the AAP's bronchiolitis symptom checker all suggest smaller, more frequent feeds. The RCH says this helps prevent dehydration for both breastfed and formula-fed babies.
2. Clear the nose before feeds. The RCH and Australia's healthdirect suggest saline nose drops or spray to clear mucus so your baby can feed more comfortably. The AAP suggests saline then gentle suction, no more than 4 times a day.
3. Keep breastfeeding. The AAP says breastfed babies don't need extra water or formula, and that expressing into a cup or bottle may help if feeding at the breast is too hard for a while.
4. Hold your baby upright when they're awake. The NHS says this can help them breathe more easily.
5. Check on them often, including overnight. The NHS suggests checking regularly through the night.
6. Keep smoke and vapour away. The RCH and Australia's healthdirect say smoking or vaping near your baby can make bronchiolitis worse.
7. Treat discomfort, not the number. The RCH says acetaminophen, or ibuprofen if your baby is over 3 months and not dehydrated, may help if they're miserable. The NHS says acetaminophen from 2 months and ibuprofen from 3 months, not at the same time. Check the label or ask a pharmacist, and never give aspirin. The NHS also says not to sponge your baby with cool water or strip off all their clothes to bring a temperature down.

Count wet diapers through the day. Fewer than usual is an early sign your baby isn't getting enough. See dehydration signs and when your baby feeds less than usual for what to look for.

What doesn't help bronchiolitis?

Several common cold remedies don't help, and some aren't safe for babies:

• Cough medicines. The RCH says cough mixtures and asthma medicines don't help bronchiolitis. The AAP says to avoid cough and cold medicines, and not to give over-the-counter cough medicine to a child who is wheezing.
• Antibiotics. Viruses cause bronchiolitis, so the RCH, Australia's healthdirect and the AAP say antibiotics won't help, although a doctor may use them if a bacterial infection develops as well.
• Steam and vaporisers. The Better Health Channel in Australia says vaporisers, humidifiers and other ways of putting steam into the air haven't been shown to help babies with bronchiolitis. The AAP takes a different view: it suggests a cool-mist humidifier if the air is dry, and its symptom checker suggests warm mist from a running shower. If you use a humidifier, the AAP says to keep it out of your baby's reach and change the water every day.
• Honey. The AAP's cough symptom checker says to avoid honey under 1 year. Never give honey to a baby under 12 months; see honey and babies.

Is it safe to raise the crib or prop my baby up?

No. It's tempting to prop up a wheezy baby, but the AAP's advice on sleeping with a stuffy nose says propping a baby on towels or pillows, or inclining the mattress, is not safe. The Lullaby Trust says not to incline, tilt or prop the mattress, crib or baby, and that doing so is unlikely to improve cold symptoms.

• Put your baby on their back for every sleep, on a firm, flat, level mattress in their own crib or bassinet.
• Keep the crib clear: no pillows, wedges, positioners or rolled towels.
• Keep their crib in your room for at least the first 6 months, day and night, in a smoke-free home.
• If your baby falls asleep in a car seat, swing or bouncer, the AAP says to move them to their own sleep space as soon as you can.

See helping a baby with a stuffy nose sleep and sleep when your baby is sick for getting through the nights, and safe sleep for the full checklist.

How can I protect my baby from RSV?

You can lower the chance of bronchiolitis by washing hands often, keeping your baby away from people with colds, not sharing cups and cutlery, and keeping your home smoke-free. The NHS says this matters most for newborns, especially premature babies or those with serious health conditions.

RSV immunization adds strong protection. There are two options: a vaccine in pregnancy that passes antibodies to your baby, or an antibody injection given to your baby. What's offered depends on where you live:

• Australia. Australia's healthdirect RSV page says the free vaccine (Abrysvo) is given between 28 and 36 weeks, protects your baby from birth to 6 months, and should be repeated in each pregnancy. It says the antibody injection (nirsevimab) is recommended for babies whose mothers weren't vaccinated or were vaccinated less than 2 weeks before birth, for babies with a higher chance of severe RSV regardless of their mother's vaccination, and for some children with risk factors in their second RSV season. Australia's National Center for Immunization Research and Surveillance (NCIRS) says the infant programs are run by each state and territory, some all year round and some seasonally, so check the rules where you live.
• UK. The NHS RSV vaccine page says you should be offered it around your 28-week antenatal appointment, in every pregnancy, and it can be given up until labor. It aims to protect each baby for the first 6 months. The NHS bronchiolitis page says children born very prematurely or with a heart or lung condition or a weakened immune system may be given an antibody injection each winter.
• US. The CDC recommends the maternal vaccine at 32 to 36 weeks during September through January in most of the US, or an antibody injection (nirsevimab or clesrovimab) for babies younger than 8 months whose mothers weren't vaccinated. Babies born October to March should have it within 1 week of birth, and some children aged 8 to 19 months at higher risk need it before their second season. The AAP's RSV guide gives the vaccine window as September through 1 March, says the pregnancy vaccine is given only once, and says most babies need one product or the other, not both.

The AAP says the pregnancy vaccine cuts the risk of RSV hospitalisation by 57% in a baby's first 6 months, and that the infant injections are about 80 to 90% effective at keeping babies out of hospital with RSV. Our vaccinations guide covers the full schedules.

When should I get help for bronchiolitis?

The RCH and Australia's healthdirect suggest seeing a doctor if you think your baby has bronchiolitis, because it can get worse quickly. Then use these tiers.

Call 911 now (or go straight to the nearest emergency room) if your baby:

• is struggling to breathe, breathing very fast, grunting, exhausted from trying to breathe, or sucking in under the ribs, at the tummy or at the neck
• pauses in their breathing, stops breathing for a few seconds, or breathes irregularly
• has blue, gray, very pale or blotchy skin, lips or tongue, including going blue in the face when coughing (on brown or black skin, check the lips, gums, palms and soles)
• has pale, sweaty skin
• is floppy, much sleepier than usual, hard to wake or can't be woken
• can't feed and shows signs of dehydration such as cool hands and feet or sunken eyes, or has had no wet diaper or pee for 12 hours
• is under 3 months and has a temperature of 38°C (100.4°F) or higher, or is 3 to 6 months old and has a temperature of 39°C (102.2°F) or higher

These come from the RCH, Australia's healthdirect, the NHS bronchiolitis page and the NHS urgent-help guide. The RCH sends a baby who goes blue when coughing, or can't feed and is dehydrated, to hospital, and the NHS bronchiolitis page lists a dry diaper for 12 hours and a fever under 3 months for an urgent doctor; we use the stricter tier for all of these.

Get medical help today (same-day doctor, after-hours doctor or your pediatrician's after-hours nurse line) if your baby:

• is feeding less than half their usual amount, has taken less than half of 2 or more feeds, or is refusing feeds
• has fewer wet diapers than usual
• is breathing faster than normal while resting, but isn't struggling
• was born prematurely, is under 10 weeks old, or has a heart, lung, neurological or immune condition, and you think they have bronchiolitis
• is under 6 months and has a cough (the AAP cough checker says contact a doctor within 24 hours at this age) or is getting worse in any way
• is very tired, irritable or doesn't seem themselves, or their cold is getting worse
• is still sick after 7 days

Talk to your doctor or pediatrician if:

• a wheeze keeps coming back, or mild wheezing lasts more than 7 days, which the AAP suggests raising with your doctor
• the cough lasts more than 3 weeks (AAP) or carries on beyond the 4 weeks the RCH describes
• you'd like advice on RSV protection for your baby or a future pregnancy

If you're unsure which tier fits, call your pediatrician's after-hours nurse line, and trust your instincts if your baby seems seriously unwell.

What's worth noting while your baby has bronchiolitis?

Jot down roughly how much your baby takes at each feed compared with usual, their wet diapers, temperatures with times, and any medicine given with the time. That makes "less than half their usual amount" easy to spot. A short video of your baby's breathing with their chest uncovered can show a doctor what you saw. Never delay getting help to finish your notes.