Which statement accurately describes emphysema?

Emphysema is accurately described by the statement regarding breathlessness due to air trapping in damaged alveoli. In emphysema, the walls of the alveoli become damaged and lose their elasticity, which impairs the normal exchange of gases and leads to the trapping of air. This results in reduced airflow during exhalation and can make breathing increasingly difficult, particularly during physical activity.

The loss of elasticity in the alveolar walls causes the air sacs to be unable to fully deflate, leading to residual air remaining in the lungs. Consequently, this trapped air can cause over-inflation of the lungs, which contributes to the sensation of breathlessness. Patients with emphysema often experience a chronic cough and may utilize accessory muscles to breathe due to the effort required to exhale effectively.

Other options do not accurately characterize emphysema, as it is not primarily related to mucus production, it is not classified as an autoimmune condition, and it is distinct from chronic bronchitis, although both conditions can coexist under the umbrella of chronic obstructive pulmonary disease (COPD).