What should you know about common causes of croup?

The upper airway in young children is narrow. When a virus causes swelling there, air movement becomes noisy and the cough may sound harsh or barking. A child may also have a hoarse voice, a runny nose or fever. Symptoms often become more noticeable at night. Croup spreads through respiratory droplets and contact with contaminated hands or surfaces.

The sound made while breathing in, called stridor, matters more than the cough alone. A clinician can assess breathing effort, colour, hydration and whether the noise occurs only when upset or also while resting.

Keep the child calm and sitting upright, because crying can make noisy breathing worse. Offer small, frequent drinks and check them regularly, including during sleep. Avoid smoke and do not use steam because it can burn the skin and has not been shown to reliably reduce airway swelling. A child health consultation can identify whether medicine is needed; severe symptoms may require nebuliser treatment.

Get emergency help if the child is struggling to breathe, has stridor while resting, pulls in the skin between the ribs, becomes unusually sleepy, drools or cannot swallow, or has blue, grey or very pale lips. Seek prompt advice if fever is high or persistent, drinking falls, or wet nappies become less frequent.

Ask how severe the airway swelling appears, whether treatment is needed, how to monitor breathing overnight, and which changes mean your child should return urgently.