Emphysema is a type of chronic obstructive pulmonary disorder (COPD), which means it is a chronic disease that causes difficulty breathing. Emphysema causes gradual damage to the air sacs (alveoli) in the lungs.
In healthy lungs, the alveoli form clusters, like bunches of grapes. In lungs with emphysema, the inner walls of the alveoli become weaker and eventually tear. This creates one larger air sac instead of several smaller ones. This causes difficulty breathing because it reduces the surface area of the lungs, which reduces the lungs’ ability to transfer oxygen to the bloodstream and expel old air. It also causes air to be trapped in the lungs, leading to even more shortness of breath.
The leading cause of emphysema is smoking.