What are obstructive pulmonary disorders?

• A. Pulmonary fibrosis and pulmonary edema only.
• B. COPD, bronchitis, emphysema, and asthma.
• C. Disorders that restrict airflow.
• D. Disorders of the immune system unrelated to lungs.

Answer: (B)

Obstructive pulmonary disorders are conditions in which airflow is impeded by narrowed or blocked airways, especially during exhalation. This increased resistance to expiration makes it hard to blow air out quickly, and spirometry typically shows a reduced amount of air expelled in the first second (lower FEV1) with a relatively lower FEV1/FVC ratio. The classic examples are COPD (which includes chronic bronchitis and emphysema) and asthma. COPD features long-term airflow limitation with structural airway changes; chronic bronchitis involves a persistent cough with mucus; emphysema reflects destruction of alveolar walls and loss of elastic recoil leading to air trapping; asthma is an inflammatory, often reversible, obstruction of the airways.

Pulmonary fibrosis and pulmonary edema, by contrast, primarily restrict lung expansion and airflow because the lungs become stiff or filled with fluid, producing a restrictive pattern rather than an obstructive one. Descriptions that center on disorders that restrict airflow don’t capture the airway narrowing that defines obstruction, and conditions unrelated to the lungs aren’t describing obstructive processes.