Final answer:
Emphysema is a disease that leads to decreased surface area for gas exchange in the lungs, often resulting from long-term exposure to irritants like tobacco smoke.
Step-by-step explanation:
The disease that results in decreased surface area for gas exchange is called emphysema. Emphysema is a type of chronic obstructive pulmonary disease (COPD) where the air sacs in the lungs (alveoli) are damaged, leading to a reduction in the surface area available for the exchange of oxygen and carbon dioxide. This impaired function can cause shortness of breath and other respiratory issues. It is often caused by long-term exposure to airborne irritants, including tobacco smoke, air pollution, and chemical fumes.