What is bronchiolitis?

Find out what bronchiolitis is, including symptoms and risk factors. 

Watch: what is bronchiolitis?

Sejal, Respiratory Paediatric Consultant, explains what bronchiolitis is, as well as common symptoms associated with the condition.

Bronchiolitis is a chest infection that most commonly affects babies and young toddlers under the age of two.

It’s caused by a virus infection and the most common virus that tends to cause bronchiolitis is respiratory syncytial virus, or RSV.

The symptoms of bronchiolitis include a slightly high temperature, some difficulty in breathing, your baby may be breathing a bit faster than usual.

There can also be some noisy breathing, which is often called wheezing.

The baby may have a cough, a persistent sort of raspy cough, and some difficulty in feeding.

They’re all of the symptoms that could be present in a child with bronchiolitis, but they may not all be present, and they can be very mild or go on to be more severe.

What is bronchiolitis?

Bronchiolitis is an infection of the smaller airways in the lungs, which are called the bronchiole or bronchioles. It’s more common in babies and very small children up to two years old and is often caused by the respiratory syncytial virus (RSV).

Conditions with similar names

Bronchiolitis is not the same as a very rare condition called bronchiolitis obliterans

Bronchiolitis is also different to bronchitis and chronic bronchitis. Bronchitis is an infection affecting the larger airways (called the bronchi) and chronic bronchitis is a form of chronic obstructive pulmonary disease (COPD).

What are the symptoms of bronchiolitis?

Bronchiolitis symptoms include:

  • sneezing 
  • a runny or blocked nose
  • a cough
  • a slightly high temperature of 38 degrees Celsius or more
  • breathing more quickly than usual
  • difficulty feeding and eating 
  • wheezing
  • becoming more tired irritable than usual.

When to get help for bronchiolitis

If your baby has mild symptoms, you can usually look after them at home. Always speak to your GP, pharmacist or another health care professional if you’re worried.

As a parent, you may know if your child seems seriously unwell and should always trust your judgement about getting help.

Watch: when to seek help if your child has bronchiolitis

Sejal, Respiratory Paediatric Consultant, explains what bronchiolitis is, as well as common symptoms associated with the condition.

If your baby has mild symptoms, you will usually be able to look after them at home without any problem. But the important thing to say is if you’re concerned about your baby and you feel something’s just not quite right, and your parental instinct is telling you something’s not right, then please just do go and seek help.

You can go to the GP, the practice nurse, or a local pharmacist to seek reassurance and that’s absolutely no problem at all.

The time when you should consider going to seek help from a healthcare professional, from your GP or the practice nurse, is if your child has a high temperature at 38 degrees and it’s not coming down despite Calpol.

If your child just isn’t feeding as well as usual, specifically if they’re not taking about a
half to three quarters of their normal feeds, then it’s time to go and see someone.

If they’re having dry nappies – if they’ve not had a wet nappy for at least 12 hours, it’s time to seek help.

And then finally if they’re just sleepy and lethargic, not waking for feeds and actually you’re having to wake them quite consistently for feeds, then it’s time to go and seek help.

The time to seek urgent help and to call 999 is if any one of these following things are happening.

If your child is really struggling to breathe and you can see they are moving their muscles in and out, their tummy’s moving in and out, that’s not right and it’s time to call 999.

The other thing is if despite the difficulty in breathing, actually they have pauses in their breathing.

They may stop breathing for 5, 10 or even up to 20 seconds, you should definitely be calling 999.

And if you see any change in the colour of your child’s skin, especially around the mouth and lips, and if you look inside, if your baby’s tongue is not nice and pink, it’s looking a bit grey or dull it’s definitely time to call 999.

Contact NHS 111 or ask for an urgent GP appointment if your baby or child

  • is under three months old and has a temperature of 38 degrees Celsius, or is older than three months old and has a temperature of 39 degrees Celsius or higher. You do not need to use a thermometer. If your baby feels hotter than usual when you touch their back or chest, feels sweaty or is shivering, then they probably have a fever 
  • has had a dry nappy for 12 or more hours, or is showing other signs of dehydration
  • is feeding or eating much less than normal
  • is unwell and they are getting worse
  • is very tired or irritable. 

Call 999 or go to A&E if your child or baby

  • is having difficulty breathing. They might make grunting noises, have long pauses in their breathing or their tummy might suck in under their ribs
  • has very pale, blue or grey lips or skin. On brown or black skin this may be easier to see on the palms of your child’s hands
  • is floppy and will not wake up or stay awake. 

Who is most at risk from bronchiolitis?

Bronchiolitis affects babies and children under two years old.

Around 1 in 3 babies will develop bronchiolitis in the first year of their life,  usually between three and six months old.

Babies and children are more at risk of developing severe bronchiolitis if they:

  • were born prematurely, especially if they were born before 32 weeks
  • have heart or lung conditions 
  • have a weakened immune system.  

Do not smoke around your child

Babies and children are also more likely to develop bronchiolitis if they breathe in cigarette smoke. Read more about how passive smoking and vaping affects your child’s lungs.

Get support

Call or WhatsApp our Helpline for support with your condition. Get advice on your medicines, symptoms or travelling with a lung condition, or just call us to say hello.

Did you find this information useful?

We use your comments to improve our information. We cannot reply to comments left on this form. If you have health concerns or need clinical advice, call our helpline on 0300 222 5800 between 9am and 5pm on a weekday or email them.

Page last reviewed:
Next review due: