Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Lung Disease & Respiratory Health Center

Font Size



Emphysema is a long-term (chronic) lung disease. In emphysema, the tiny air sacs (alveoli) at the end of the airways in the lungs are damaged. When the air sacs are damaged or destroyed, their walls break down and the sacs become larger. These larger air sacs move less oxygen into the blood. This causes difficulty breathing or shortness of breath that gets worse over time. After air sacs are destroyed, they cannot be replaced.

Emphysema is a form of chronic obstructive pulmonary disease (COPD). It is usually caused by smoking. A rare type of emphysema is caused by the lack of a substance in the lungs called alpha1-antitrypsin. This type of emphysema is usually inherited.

ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Specialist Medical ReviewerKen Y. Yoneda, MD - Pulmonology

Current as ofSeptember 9, 2014

WebMD Medical Reference from Healthwise

Last Updated: September 09, 2014
This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

Today on WebMD

man coughing
You may not even know you have it.
blood clot
Signs of this potentially fatal complication.
man coughing
When a cold becomes bronchitis.
human lungs
Causes behind painful breathing, fluid buildup.

chest x-ray
Bronchitis Overview
Copd Myth Fact Quiz
Energy Boosting Foods

woman coughing
Lung xray and caduceus