Air trapping is a characteristic feature of which condition?

• A. Restrictive lung disease
• B. Obstructive lung disease
• C. Asthma only
• D. Pneumonia only

Answer: (B)

Air trapping is primarily associated with obstructive lung disease. This condition typically involves the obstruction of airflow, which makes it difficult for patients to exhale completely. As a result, air becomes trapped in the lungs, leading to over-inflation and decreased overall lung function.

In obstructive lung diseases, such as chronic obstructive pulmonary disease (COPD) and asthma, the excessive buildup of air occurs due to narrowed airways from inflammation, mucus production, or excessive bronchospasm. This causes a significant increase in the residual volume of air left in the lungs after exhalation.

Restrictive lung disease, on the other hand, is characterized by reduced lung volume and decreased compliance, making it difficult for individuals to fill their lungs with air rather than to expel it. Conditions like pneumonia or specific diseases affecting the pleura or interstitial lung tissue may limit lung expansion but do not typically result in air trapping.

While asthma can indeed lead to air trapping during an acute episode, the broader category of obstructive lung disease encompasses various conditions that result in this phenomenon. Therefore, referring specifically to obstructive lung disease captures the essential characteristic of air trapping across multiple disorders rather than being confined to asthma alone or pneumonia.