meaning of emphysema
emphysema. A disease in which the alveoli (tiny air sacs) of the lungs are damaged. Their separating walls are destroyed and the alveoli are enlarged.This leads to a decrease in the surface area available for gas exchange, and breathing becomes very difficult.mphysema. A disease in which the alveoli (tiny air sacs) of the lungs are damaged. Their separating walls are destroyed and the alveoli are enlarged.