Emphysema gradually damages the air sacs (alveoli) in your lungs, making you progressively more short of breath. Emphysema is one of several diseases known collectively as chronic obstructive pulmonary disease (COPD).

Smoking is the leading cause of emphysema.

Your lungs' alveoli are clustered like bunches of grapes. In emphysema, the inner walls of the air sacs weaken and eventually rupture — creating one larger air space instead of many small ones. This reduces the surface area of the lungs and, in turn, the amount of oxygen that reaches your bloodstream.

When you exhale, the damaged alveoli don't work properly and old air becomes trapped, leaving no room for fresh, oxygen-rich air to enter. Treatment may slow the progression of emphysema, but it can't reverse the damage.

Symptoms Causes Risk factors Complications Prevention

You can have emphysema for many years without noticing any signs or symptoms. The main symptom of emphysema is shortness of breath, which usually begins gradually. You may start avoiding activities that cause you to be short of breath, so the symptom doesn't become a problem until it starts interfering with daily tasks. Emphysema eventually causes shortness of breath even while you're at rest.

When to see a doctor

See your doctor if you've had unexplained shortness of breath for several months, especially if it's getting worse or it's interfering with your daily activities. Don't try to attribute it to your deconditioning or age or weight. Seek immediate medical attention if:

  • You're so short of breath, you can't climb stairs
  • Your lips or fingernails turn blue or gray with exertion
  • You're not mentally alert

© 1998-2015 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. Terms of use