Asthma, chronic inflammatory respiratory disease characterized by periodic attacks of wheezing, shortness of breath, and a tight feeling in the chest. A cough producing sticky mucus is symptomatic.
The symptoms often appear to be caused by the body's reaction to a trigger such as an allergen certain drugs, an irritant (such as cigarette smoke or workplace chemicals), exercise, or emotional stress.
These triggers can cause the asthmatic's lungs to release chemicals that create inflammation of the bronchial lining, constriction, and bronchial spasms. If the effect on the bronchi becomes severe enough to impede exhalation, carbon dioxide can build up in the lungs and lead to unconsciousness and death. Following a steady 30-year decline, asthma deaths in the United States, especially among poor, inner-city blacks and among the elderly, began to rise from the late 1970s through the early 1990s.