Three particular types of airway obstruction are:
Bronchospasm occurs when the smooth muscles surrounding the airway tighten. If you are asthmatic, your sensitive and easily irritated airways can spasm at times due to a relatively minor stimulus (e.g. breathing in cold air, exposure to allergens, exercise, cigarette smoke, etc.). Fortunately, partial or total reversibility of bronchial tube spasm is a primary characteristic of bronchial asthma early in the course of the disease.
Due to mast-cell chemical release and airway inflammation, the membranes lining the inside of the bronchial tubes swell. This swelling contributes to narrowing of the passageways.
Airway obstruction may further result from the thick, sticky mucus and mucous plugs produced during an asthmatic attack. If you are asthmatic, you may frequently complain of feeling "congested" from mucus accumulation, or say that "if the mucus could only be coughed up," symptoms would be relieved. However, in a flare of asthmatic symptoms, as quickly as mucus is coughed up, new mucus is produced. Symptom relief is best achieved by treating the underlying bronchial inflammation and obstruction.