WebMD: Better Information. Better Health.
  • Bookmark This Page
  • Site Map
  • Sign up for WebMD Newsletters

Information and Resources

Font Size
A
A
A

Understanding Pneumonia - the Basics

What Is Pneumonia?

Pneumonia is when the lungs get inflamed, usually due to infection. Breathing in certain chemical fumes can also cause pneumonia. It's a more common problem than most people think. Usually it's a mild disease, but some forms are very dangerous. In all cases you'll need a doctor's advice.

Pneumonia can affect just one lobe or section of the lung or many sections of the lung. When more than one lobe or section is affected, it's called double pneumonia.

Many different kinds of germs infect the lungs and cause pneumonia. Infected lungs leak fluids and shed dead cells. This material clogs up air sacs and makes it hard for the lungs to do their job of getting oxygen into the blood. Without enough oxygen, none of the cells in your body work as they should.

Pneumonia generally lasts about two weeks. Even healthy people may feel tired or weak for a month or more after the lungs clear up.

What Causes Pneumonia?

Viruses cause many cases of pneumonia but  bacteria are the most common cause of pneumonia in adults over the age of 30. Fungi can also cause pneumonia.

Many of these germs are all around us. They usually can't get past a healthy person's natural defenses. That's why pneumonia is most common in elderly people, in cigarette smokers, in alcoholics, and in people suffering from other diseases such as the flu.

WebMD Medical Reference

Reviewed by Jonathan L Gelfand, MD on June 01, 2007
webMD Video

click to expand/contract  IBS Trigger Foods

Everyone's IBS is different, but most sufferers have these symptom triggers in common.

Watch Video

click to expand/contract  Hunger vs. Cravings

click to expand/contract  Killer Abs

click to expand/contract  Truth About Naps

click to expand/contract  Better Sex Exercises

Most Popular Stories