What lung condition is defined by an abnormal increase in lung volumes?

Emphysema is characterized by an abnormal increase in lung volumes, particularly functional residual capacity (FRC) and total lung capacity (TLC). This condition results from the destruction of alveoli and the loss of elastic recoil, causing air to become trapped in the lungs during expiration. As the alveolar walls are damaged, the surface area for gas exchange is reduced, leading to ventilation-perfusion mismatches and decreased oxygenation.

The loss of elastic recoil means that the lungs cannot fully expel air, resulting in hyperinflation and increased lung volumes. Thus, emphysema exemplifies a restrictive pulmonary status where the lungs hold more air than normal due to structural changes. This is contrasted with the other options, which do not primarily feature this specific increase in lung volumes. For example, chronic bronchitis involves airway inflammation and mucus production rather than increased lung volumes; pneumonia is primarily an infectious process affecting lung tissue rather than volumes; and asthma involves reversible airway obstruction, not a permanent increase in lung volumes.