Upper respiratory infections. Cold and flu, bronchitis (infection of the large airways), or sinus infections can cause an asthma attack.

Inhaled allergens. Eighty percent of people with asthma have allergies to airborne substances such as tree, grass and weed pollens, mold, animal dander, dust mites and cockroach particles.

Medications. Many people with asthma are sensitive to aspirin and other anti-inflammatory drugs like ibuprofen (Advil, Motrin), naproxen (Aleve, Naprosyn), ketoprofen (Orudis) and beta-blockers (used to prevent migraine headaches and treat heart disease, high blood pressure and glaucoma).

Food and food additives. Certain foods contain substances that can trigger asthma symptoms.

Exercise. Strenuous exercise can cause a narrowing of the airways in about 80% of people with asthma.

(Courtesy of webmd.com)