What causes my asthma to act up?

* Allergens: These are substances that trigger an allergic reaction, such as pollen, dust mites, pet dander, and mold.

* Irritants: These are substances that can irritate the airways, such as smoke, pollution, and chemicals.

* Exercise: Exercise can trigger asthma in some people.

* Cold air: Cold air can trigger asthma in some people.

* Stress: Stress can trigger asthma in some people.

* Illness: Illnesses such as the common cold and flu can trigger asthma in some people.

* Certain medications: Some medications, such as aspirin and beta-blockers, can trigger asthma in some people.

* Hormonal changes: Hormonal changes, such as those that occur during puberty and pregnancy, can trigger asthma in some people.