What does emphysema describe?

Emphysema is a chronic lung condition that primarily affects the air sacs (alveoli) in the lungs. It is characterized by the destruction of the alveolar walls, leading to enlarged air spaces that trap air, making it difficult for individuals to fully exhale. This trapping of air results in an over-inflation of the lungs, which is correctly described by the concept of swelling due to contained air. Individuals with emphysema often experience symptoms like shortness of breath, wheezing, and a persistent cough, reflecting the underlying pathophysiology of air retention and impaired gas exchange.

The other options presented do not correctly define emphysema. Abnormal growth of tissue refers to different conditions, such as tumors or neoplasms. Infection in the bronchi is indicative of bronchitis, a different respiratory issue primarily involving inflammation and infections of the bronchial tubes. Inability to absorb nutrients is associated with gastrointestinal disorders and not lung pathology. Each of these alternatives addresses distinctly different health issues, highlighting why the trapping of air and resulting lung swelling through emphysema makes the choice the most accurate description of the condition.