Healthy Lungs

In healthy lungs, the airways carry air to the lungs, then get smaller and smaller like branches of a tree. At the end of each tiny branch, there are many small air sacs — like tiny balloons.

In healthy people, each airway is clear and open. Each tiny air sac fills up with air. Then the air quickly goes out.

Lungs with COPD

When you have COPD (chronic obstructive pulmonary disease), the openings of the airways are smaller, thus allowing less air to get into the lungs.

In people with COPD, the air sacs no longer bounce back to their original shape. The airways can also become swollen or thicker than normal, and mucus production might increase. The airways are blocked, or obstructed, making it even harder to get air out of the lungs.

Your doctor can help you understand the problems you have with your lungs.