Which disorder is classified as obstructive?

• A. COPD.
• B. Pulmonary edema.
• C. Pulmonary fibrosis.
• D. Pulmonary embolism.

Answer: (A)

Obstructive lung disorders are identified by airflow limitation, especially during exhalation, due to narrowed or blocked airways. This shows up as a reduced expiratory flow (lower FEV1) and a decreased FEV1/FVC ratio on lung function tests, often with air trapping and sometimes hyperinflation. COPD is a classic obstructive condition because it involves chronic airway inflammation and structural changes that make it hard to exhale air from the lungs.

Pulmonary edema and pulmonary fibrosis, by contrast, primarily reduce lung compliance and total lung capacity, producing a restrictive pattern on testing—both FEV1 and FVC drop, but the FEV1/FVC ratio is often normal or increased. Pulmonary embolism is a vascular problem that disrupts blood flow and gas exchange rather than causing airway narrowing, so it isn’t classified as obstructive. Therefore, the disorder that is obstructive is COPD.