About Asthma Triggers

There are many asthma triggers. Two large categories of triggers are allergens and irritants.

Allergens are substances that cause no problem for a majority of people but which trigger an allergic reaction in some people. During an allergy attack, the body releases chemicals called mediators. These mediators often trigger asthma episodes.

Irritants such as cold air, cigarette smoke, industrial chemicals, perfume, and paint and gasoline fumes can trigger asthma. These irritants probably trigger asthma symptoms by stimulating irritant receptors in the respiratory tract. These receptors, in turn, cause the muscles surrounding the airway to constrict, resulting in an asthma attack.

Viral infections are the leading cause of acute asthma attacks. Surprisingly, bacterial infections, with the exception of sinusitis, generally do not bring about asthma attacks.

Since Americans spend up to 90% of their time indoors, exposure to indoor allergens and irritants may play a significant role in triggering asthma episodes.

The following is a list of some of the indoor environmental asthma triggers:

• Secondhand (cigarette) smoke
• Cockroaches
• Dust mites
• Molds
• Pets and other animals with fur or feathers

Additional triggers includes:

• House dust
• Ozone
• Combustion by-products
• Pollen (tree, grass and weed)