Asthma in children

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.


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


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

Colds and flu

Infections of the airways are common triggers.

Weather conditions

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


Physical activity can make asthma worse, particularly in cold weather. But exercise is important for your child’s health so they shouldn’t avoid it.  They should take their reliever inhaler before exercise. If they still get symptoms while exercising, they should have a rest, take their reliever inhaler and wait until they feel better before starting again.

Strong emotions

Children can have lots of emotions in one day, and strong emotions, such as the excitement around a birthday, can trigger symptoms.

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Last medically reviewed: September 2016. Due for review: September 2019

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.