Asthma is an inflammatory disorder of the airways, which causes attacks of wheezing, shortness of breath, chest tightness, and coughing. When an asthma attack occurs, the muscles surrounding the airways become tight and the lining of the air passages swells. This reduces the amount of air that can pass by.
Common asthma triggers include:
Animals (pet hair or dander)
Changes in weather (most often cold weather)
Chemicals in the air or in food
Respiratory infections, such as the common cold
Strong emotions (stress)