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Patient information A-Z

What is bronchiolitis?

Bronchiolitis is a common respiratory infection affecting babies and young children up to two years of age. It affects up to one in three babies during the bronchiolitis season (November to March) in the UK and causes problems with breathing and feeding.

What is the cause of bronchiolitis?

Bronchiolitis is caused by viruses. The most common virus is respiratory syncytial virus (RSV). RSV is spread by tiny water droplets and thrives in the nose and throat. It causes the smallest airways in the lungs to become swollen and full of mucus. This can make it more difficult for your baby to breathe and feed.

Babies at higher risk of developing a more serious illness are those born prematurely or with lung or heart conditions.

Can I prevent bronchiolitis?

No. The virus that causes bronchiolitis in babies also causes coughs and colds in older children and adults, so it is very difficult to prevent.

What are the symptoms of bronchiolitis?

Bronchiolitis starts with cold symptoms such as a runny nose, rasping, and persistent dry cough.

Your baby may develop a mild temperature for two to three days. If your baby has a temperature give him or her paracetamol (for example, Calpol or Disprol). You must follow the instructions that come with the paracetamol carefully.

Fast breathing, difficulty breathing and wheezing (high pitched whistle noise) may develop.

Sometimes, in very young babies, bronchiolitis may cause them to have brief pauses in their breathing.

As breathing becomes more difficult, your baby may not be able to take the usual amount of milk by breast or bottle. You may notice fewer wet nappies than usual.

  • Your baby may be sick after feeding and become irritable.

The muscles in between the ribs suck in with each breath leading to more difficulty with feeding.

Bronchiolitis is caused by a virus so antibiotics won’t help.

Make sure your baby is not exposed to tobacco smoke. Passive smoking can seriously damage your baby’s health. It makes breathing problems like bronchiolitis worse.

How long does bronchiolitis last?

Most babies with bronchiolitis get better within about two weeks. They may still have a cough for a few more weeks.

Your baby can go back to nursery as soon as he or she is well enough (that is feeding normally and with no difficulty breathing).

There is usually no need to see your doctor if your baby is recovering well. If you are worried about your baby’s progress, discuss this with your doctor or health visitor.

The cough may last for up to six weeks.

When should I get advice?

Contact your GP if:

  • You are worried about your baby.
  • Your baby is having difficulty breathing.
  • Your baby is taking less than half his or her usual feeds over two to three feeds, or has no wet nappy for 12 hours.
  • Your baby has a high temperature.
  • Your baby seems very tired or irritable.

When should I call an ambulance?

  • If your child has a lot of difficulty in breathing.
  • If your child becomes floppy, agitated or confused.
  • If your child’s lips or face become pale or blue.

During coronavirus (COVID-19)

Whilst COVID-19 is infectious to children it is rarely serious. If your child is unwell it is likely to be a non-COVID 19 illness, rather than COVID 19 itself.

Please continue to follow up to date government advice.

Please do call NHS 111 & follow the advice from The Royal College of Paediatrics and Child Health.

Hospital treatment for bronchiolitis

About 1 in 5 children with bronchiolitis may need hospital admission.

When in hospital

Your baby will be examined by a doctor and assessed regularly by a nurse.

During COVID-19 pandemic all staff will be wearing appropriate personal protective equipment (PPE) to protect you & your child appropriately; this will be explained to you on admission.

Your baby’s oxygen levels will be checked using an oximeter placed on a finger or toe. It measures the oxygen in your baby’s blood, and helps doctors and nurses to assess your baby’s breathing.

If your baby needs help to breathe or feed, he or she may need to stay in hospital.

One parent/carer will be able to stay with your baby while he or she is in hospital.

Oxygen may be given via mask or fine tubes into the nose (nasal cannula/high flow).

If your child has problems feeding he or she may be fed through a feeding tube. This a small plastic tube passed through the child’s nose or mouth into the stomach.

Some babies may need to be fed via a drip to make sure they are getting enough fluids.

Seriously ill babies may require more specialised intensive care for help with their breathing.

Your child may be given paracetamol every six hours if required.

Your child may be nursed in a separate room or with other babies who have the same type of virus.

You will need to wash your hands, or use alcohol gel frequently when caring for your child.

Visiting restrictions may be recommended to prevent the spread of infection.


The RSV virus, which causes bronchiolitis, is very infectious and is responsible for many colds in children and adults. Ensure that your baby does not come into contact with other young children to reduce the spread of infection.

Babies who are breast-fed and live in a non-smoking family are less likely to have severe disease.

After leaving hospital

  • Your child will be discharged from hospital when oxygen treatment has stopped and they are feeding.
  • Ask your GP or health visitor for advice if you become worried about your baby.

Long term effects of having had bronchiolitis

Your baby may have a cough and wheeze for some time after the first infection.

Most babies recover well from bronchiolitis and do not have long term breathing problems.

However, RSV bronchiolitis may cause recurrent wheezing with each cold your child has.

Useful contact numbers

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151