HOME MEDICAL ENCYCLOPEDIA ONLINE TOOLS HEALTH INFO
pneumonia

Images (Click to view larger image)
  • Lung abscess
  • Lung X-ray
  • Pneumonia

Blaussen Videos
Pneumonia Movie

Definition

Pneumonia is an infection of the lungs that can be caused by many different microorganisms. These include viruses, bacteria, parasites, and fungi.

What is going on in the body?

Pneumonia occurs when an infectious organism causes inflammation in the lungs. The air sacs fill with liquid and mucus. This means they can't deliver oxygen as well to the blood vessels.

What are the signs and symptoms of the infection?

The symptoms of pneumonia vary depending on the organism but may include the following:

What are the causes and risks of the infection?

Pneumonia is a fairly common infection that affects people of all ages. Some of its more common causes are as follows: The following factors can increase a person's risk of developing severe pneumonia:

What can be done to prevent the infection?

The pneumonia vaccine can prevent pneumonia that is caused by bacteria. Because pneumonia is a common complication of the flu, an annual flu shot can also help to prevent pneumonia.

Pneumonia often follows common respiratory infections. So one of the best ways to prevent it is to be on the lookout for any symptoms of respiratory illness that hang on more than a few days. Healthy living habits can also help. For example, the following healthy habits can all help increase resistance to respiratory illness:

These habits can also spur a faster recovery times from illness.

How is the infection diagnosed?

Diagnosis of pneumonia begins with a medical history and physical exam. A chest X-ray can confirm the diagnosis. Sometimes the germ causing the pneumonia can be found in the person's sputum or blood, but often no specific organism can be identified.

What are the long-term effects of the infection?

Usually, there are no long-term effects from pneumonia. Sometimes, lung damage can cause a lasting decrease in lung function.

What are the risks to others?

Most of the organisms that cause pneumonia can be spread from person to person through coughing or sneezing.

What are the treatments for the infection?

Some types of pneumonia can be treated with antibiotics or antiviral medicines. Oxygen, and sometimes a ventilator, may be needed to help a person breathe.

What are the side effects of the treatments?

Antibiotics may cause rash, upset stomach, or allergic reactions.

What happens after treatment for the condition?

Most people recover completely and can resume normal activities.

How is the condition monitored?

The healthcare professional may order periodic chest X-rays until the infection is completely gone. Any new or worsening symptoms should be reported to the healthcare professional.


Author:Danielle Zerr, MD
Date Written:11/29/99
Medical Review:Gaylen Kelton, MD
Date Written:10/7/2006
Reviewer:Walt Larimore, MD
Date Reviewed:10/28/2006
Contributors
Potential conflict of interest information for reviewers available on request