Which statement best describes emphysema?

• A. It is a reversible condition that resolves in days.
• B. It affects only the chest wall.
• C. Emphysema involves damage to the alveoli leading to impaired gas exchange.
• D. It is caused by a bacterial infection of the lungs.

Answer: (C)

Emphysema is a chronic lung condition where the walls of the alveoli are damaged, causing enlargement of air spaces and a loss of surface area for gas exchange. This destruction reduces the lungs’ ability to transfer oxygen into the blood and remove carbon dioxide, so gas exchange becomes impaired. The damage is permanent and typically progressive, not something that reverses in a few days. It involves the lung tissue itself, not just the chest wall. It is not caused by a bacterial infection, although infections can worsen symptoms in someone who has emphysema.

So the statement that best describes emphysema is that it involves damage to the alveoli leading to impaired gas exchange.