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What Is Emphysema?

Emphysema is a lung disease that limits the movement of air in and out of your lungs, making breathing harder. Emphysema is most often caused by heavy, long-time cigarette smoking. Emphysema is one of a group of conditions called chronic obstructive pulmonary disease (COPD).

Healthy Lungs

Bronchiole and alveolar sacs with blood supply.

  • Inside the lungs are branching airways made of stretchy tissue. Each airway is wrapped with bands of muscle that help keep it open. Air travels in and out of the lungs through these airways.

  • The tubes branch into smaller passages called bronchioles. These end in clusters of balloon-like sacs called alveoli.

  • Blood vessels surrounding the alveoli move oxygen into the blood. At the same time, the alveoli remove carbon dioxide or waste from the blood. The carbon dioxide is then exhaled.

When You Have Emphysema

Collapsed bronchiole and alveolar sacs with emphysema.

  • Airways become damaged. When the lung tissue loses its stretchiness, the surrounding airways collapse more easily and trap air in the lungs. 

  • Damaged airways collapse when you exhale, causing air to get trapped in the alveoli. This trapped air makes breathing harder.

  • Over time, the air sacs lose their clustered shape and don't work well. And, less oxygen enters the blood.

  • The air sacs enlarge and the diaphragm flattens. This makes it even harder for the lungs to move air in and out.

Online Medical Reviewer: Akin, Louise, RN
Online Medical Reviewer: Holloway, Beth, RN, M.Ed.
Online Medical Reviewer: Images reviewed by StayWell medical illustration team.
Date Last Reviewed: 6/18/2014
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