How does lung compliance change in emphysema?

In emphysema, lung compliance is increased primarily due to the destruction of elastin fibers and the loss of elastic recoil in the lung tissue. During normal breathing, the lungs expand and contract due to the elastic properties that allow them to return to their original shape after inflation. However, with emphysema, the alveolar walls become damaged and the lung tissue loses its elasticity, resulting in a greater volume of air being trapped in the lungs.

As a consequence, the lungs become more distensible, which means they can expand more easily; however, this increased compliance also leads to difficulties in expelling air effectively. Patients often find it challenging to exhale, which results in air trapping and hyperinflation of the lungs. Therefore, while the lungs can expand more easily, this change in compliance also contributes to the pathophysiological challenges faced by individuals with emphysema, highlighting the disconnect between compliance and overall lung function.