Asthma triggers

Asthma is triggered by a variety of things. Some people will have a lot of triggers, while others may only react to one or two items.

Keep a note of when you or your child gets symptoms of asthma. This may help you to identify what the triggers are. Some triggers are easier to avoid than others.

Colds and influenza

The most common trigger for asthma attacks in children is a cold or influenza (flu). These are more common in winter and are difficult to avoid. If your child develops signs of asthma with a cold, follow your asthma action plan.


Young children who breathe in the cigarette smoke of people around them (passive smoking) have a higher risk of wheezing and having an asthma attack. Exposure to cigarette smoke can also cause children to be more likely to develop asthma than if they had not been exposed to smoke.

Smoking during pregnancy can affect lung development and increases the risk of the child developing asthma.

Exercise and play

Exercise and play are healthy activities and should not be avoided. If exercise is a trigger, you should use your blue puffer 5 to 10 minutes before sport and do some warm up exercises.

Read more about asthma medications and inhaler devices.

Wood fires and bush smoke

Smoky air can trigger asthma and is best avoided. Consider using electricity or flued gas fires instead of a wood fire. During bush fires, when the air is smoky, you may need reliever medication if symptoms develop.

Read more about the health effects of wood smoke and bushfires.

Weather changes

Humid weather or breathing in cold air may trigger asthma symptoms.


Some medications such as aspirin may trigger asthma, although this type of reaction is rare in children. Royal jelly and echinacea may also contribute to asthma. Always discuss alternative or natural remedies with your doctor.

Chemicals and strong smells

Fumes from paint, cleaning products such as bleach and perfumes may trigger asthma symptoms. Avoid exposure to these in confined spaces without adequate ventilation, such as an open window.


Allergy occurs as a result of your immune system reacting to certain substances, such as food, pollens, grasses, dust, mould and pets. An allergen is a substance which causes the allergic response. Talk to your doctor if you think you need specialised allergy testing.

Foods and additives

Food allergies causing asthma are rare. Foods should not be eliminated from the diet unless there is a proven allergy.

Additives that may trigger asthma include:

  • sulphites, a preservative numbered 220-228
  • tartrazine, yellow food colouring number 102
  • monosodium glutamate (MSG), a flavour enhancer numbered 620-625.

Read more about food additives.

Pollens and grasses

Allergic responses to pollens and grasses usually result in symptoms of hay fever such as a runny itchy nose and red itchy eyes.

Many people who have hay fever also have asthma and find exposure to these triggers worsen their asthma. It may be worse in spring and windy days or after thunderstorms. Talk to your doctor about troublesome symptoms and appropriate treatment.

House dust mites

House dust mites live in furnishings and carpets. You can reduce their effects by washing the sheets in hot water once a week (or adding tea tree oil or eucalyptus oil to the wash), damp dusting and removing soft toys from the bed.


Mould and dampness indoors have been associated with asthma attacks. Learn more about the mould and dampness.

Pets and pests

Common pets and pests that cause allergy and asthma are cats, dogs and cockroaches. It does not matter whether they are long haired or short haired pets, they can all cause allergies. There is no consistent evidence that early exposure to or avoidance of pets protects against developing an allergy to that pet. If the family already has pets, it is not necessary to remove the pet from the house, unless there is a proven allergy. If allergic, minimise contact with the pet, and keep the pet out of the bedrooms and living areas, wash the pet regularly and vacuum floors weekly.


Child and Adolescent Health Service – Community Health (CAHS CH)

This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.

Link to HealthyWA Facebook page