If you think your child may have bronchiolitis, you should take them to see your GP, or dial 999 for an ambulance if they have any of the following symptoms:

• Difficulty breathing, or exhaustion from trying to breathe (you might see the muscles under your baby's ribs sucking in with each breath, and they may be pale and sweaty).
• Rapid breathing rate of more than 40 breaths a minute.
• Breathing stops for more than 10 seconds at a time (known as recurrent apnoea).
• Skin begins to turn ashen or blue, especially around the lips or fingernails (known as cyanosis).

If you see your GP, they may check for wheezing and listen to your child's lungs using a stethoscope. They may also check for signs of dehydration if your child has been vomiting or refusing to eat and drink. These include sunken eyes, a dipped fontanelle in babies (the soft spot on the top of the head), dry mouth and skin, lethargy and producing little or no urine.

In some cases, your GP may want to do further tests to confirm a diagnosis, such as a chest x-ray, a mucus sample test or a blood test.

Chest x-ray

This is used to check for swelling of the airways in your child's lungs. It can also be used to check for signs of pneumonia, which can develop alongside bronchiolitis in some rare cases, and can reveal whether your child has inhaled something small that may be affecting their breathing.

Mucus sample test

Your GP may use a swab to collect a sample of mucus from your child's nose, in order to determine which virus is causing your child's bronchiolitis.

Blood test

Your GP may need to check if your child's white blood cell count is up, which shows whether your child's body is fighting an infection. A blood test can also determine whether the level of oxygen in your child's blood has gone down