Bronchi and bronchioles are occluded by thick, tenacious mucous plugs.  Asthma patients have attacks of severe dyspnea with coughing and wheezing. A state of unremitting bronchospasm, status asthmaticus, can be fatal.

Thickened basement membrane. Prominent eosinophils in submucosa of bronchus. The most common type of asthma is atopic, is triggered by various environmental agents, and begins in childhood. Type I hypersensitivity is involved with many cell types and inflammatory mediators.

The lumen of a bronchus contains mucus and desquamated epithelial cells. Also seen in asthma but not illustrated here is hypertrophy of smooth muscle in the bronchial wall. Not all asthma is atopic. Asthma can be provoked by viruses, aspirin sensitivity, and various fumes, gases, and chemicals to which workers in certain industries are exposed.

From the slide collection of the late Dr. Charles Kuhn