Inflamed airways become overly sensitive, and when exposed to pollution, allergens, or other everyday irritants, the muscles surrounding the airways constrict. This tightening narrows the airway passages and restricts the smooth flow of air as a person breathes. Airflow may be further obstructed by excess mucus, which is secreted in response to the inflammation and plugs the smaller airways. The classic asthma symptom of wheezing is the sound of air trying to find its way through obstructed airways as the person exhales. The severity of symptoms varies widely from one person to another and from one attack to the next.
Some attacks are just a nuisance.
Others quickly become life threatening. For some, asthma causes only mild and occasional symptoms. For others, it makes breathing a daily struggle. Select continue or choose from the Table of Contents. You should consult with your physician before making any major changes in your lifestyle or health care regimen.