Asthma in children

What are the triggers of asthma in children?

Triggers are things that bring on the symptoms of asthma. They don’t cause asthma, but if your child already has it, they can make the symptoms worse.

Here are some common asthma triggers:


If your child is allergic to something, their allergy could trigger asthma symptoms. Common things that cause an allergic reaction are certain foods, pollen, mould, house dust mites and pets.


These are things that irritate the airways when they are breathed in, such as tobacco smoke, air pollution and car fumes.

Colds and flu

Infections of the airways are common triggers.


Cold weather can bring on asthma, as well as very hot weather, damp weather and thunderstorms.


Regular exercise is important for good health – encourage your child to be active. Some children may find that physical activity makes their asthma worse, particularly in cold weather. If that happens, they should have a rest, take their reliever inhaler and wait until they feel better before starting again.

If your child keeps getting asthma symptoms when they exercise, their asthma control may not be effective. Getting their treatment reviewed may help.

Stress and strong emotions

Symptoms can get worse at times of stress or strong emotions. Children and teenagers experience stronger emotions than adults, and these may act as an asthma trigger. This is less likely to happen if your child’s asthma is well-controlled.

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Last medically reviewed: September 2019. Due for review: September 2022

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.