Understanding Asthma Triggers

Triggers are things that cause you to have asthma symptoms. Some triggers you can stay away from completely. Others you can plan for and adjust to. Use this sheet to help you know your triggers.

Man holding a small dog.

What are triggers?

Triggers irritate your lungs and lead to asthma flare-ups. Some examples are:

  • Irritants, such as tobacco smoke or air pollution. These are a concern for all people with asthma.

  • Allergens or substances that cause allergies, like pets, dust mites, or pollen

  • Special conditions. These include being ill with a cold or the flu, or certain kinds of weather, including changes in weather. These differ from person to person.

  • Exercise can trigger asthma in some people. If exercise is one of your triggers, you can learn how to exercise safely.

What triggers your asthma?

Which of these common triggers cause your asthma to flare up? Check all that apply to you.


? Tobacco smoke (smoking or secondhand smoke)
? Smoke from fireplaces
? Vehicle exhaust
? Smog or air pollution
? Aerosol sprays
? Strong odors, such as perfume, incense, or cooking odors
? Household cleaners, such as ammonia or bleach


? Cats
? Dogs
? Birds
? Dust or dust mites
? Pollen
? Mold
? Cockroaches

Other triggers:

? Cold air
? Hot air
? Weather changes
? Exercise
? Certain foods or food ingredients (such as sulfites)
? Medicines
? Emotions such as laughing, crying, or feeling stressed
? Illness such as colds, flu, and sinus infections

Allergies and allergy treatment

People with asthma often have allergies. If you have allergies, or think you have them, talk with your healthcare provider about testing and treatment. Allergy testing can find out exactly which allergens affect you. Types of tests include:

  • Skin tests. A small amount of each allergen is put on the skin. Sites are then looked at for an allergic reaction. This could be redness, swelling, or itching. In general, the greater the reaction, the stronger the allergy.

  • Blood tests. A blood test can show sensitivity to the allergen.

Exposing a person to gradually larger amounts of an allergen can help the body build up a tolerance. This is the purpose of allergy shots (immunotherapy). For this therapy, injections are given over a period of years. At first, you get injections with a very small amount of allergen about once a week. As treatment goes on, the amount of allergen is gradually increased to a certain level. Eventually, you have the injections less often. This therapy can take up to a year to start working. But it can be very effective to manage certain allergies over time.