It is important to know what things make your asthma worse. These are called asthma "triggers." Avoiding them is your first step toward feeling better. The most common asthma triggers are respiratory tract infections caused by viruses, such as the flu and common cold. Other triggers are cold and dry air, mold, pets, dust, grasses, pollen, cockroaches, odors from chemicals, and smoke from cigarettes.
Review Date 4/5/2020
Updated by: Denis Hadjiliadis, MD, MHS, Paul F. Harron Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.