Which lung condition is characterized by a prolonged expiration phase on auscultation?

The condition characterized by a prolonged expiration phase on auscultation is Chronic Obstructive Pulmonary Disease (COPD). In COPD, the airway structures are damaged, leading to increased resistance during expiration. This results in air trapping and a delay in the emptying of the lungs compared to the inspiratory phase, which can manifest as a prolonged expiration during auscultation.

Patients with COPD often experience a decreased airflow due to narrowed airways, inflammation, and loss of elastic recoil in the lungs. As a result, the effort to expel air becomes extended, leading to longer expiration times. This distinct sound on auscultation is a key clinical feature that helps differentiate COPD from other respiratory conditions.

Asthma, while also associated with airway obstruction, usually presents with a variable expiratory phase dependent on the presence of bronchospasm rather than a consistent prolonged phase as seen in COPD. Pneumonia typically presents with crackles or rales rather than a prolonged expiration phase, and interstitial lung disease primarily affects lung compliance and often leads to a restrictive pattern rather than obstructive airflow characteristics.