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Definition

Pneumonia is an infection of the lungs. It affects the small airways and air sacs in the lungs.

Development of Pneumonia in the Air Sacs of the Lungs
pneumonia lung fluid
The normal exchange of gases is interrupted by the build up of fluids.
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Pneumonia is sometimes described by where and how you were infected. Types of pneumonia include:

  • Community-acquired—from the community, such as a school, gym, or at work
  • Nosocomial—in a hospital or healthcare setting
  • Aspiration—happens when foreign matter is inhaled into the lungs, such as food, liquid, saliva, or vomit

Causes

Pneumonia may be caused by:

  • Infection from specific types of:
    • Bacteria
    • Viruses
    • Fungi
  • Aspiration
  • Other specific germs
  • Chemical exposure and irritation

Aspiration
lung aspiration food
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Risk Factors

Pneumonia is more common in older adults. Other factors that may increase your chance of developing pneumonia include:

Symptoms

Pneumonia may cause:

  • Cough
  • Chest pain
  • Increased mucus production
  • Fever and chills
  • Trouble breathing
  • Weakness

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor may suspect pneumonia based on your symptoms, and breath and lung sounds. Tests can confirm diagnosis and determine the specific germ causing the pneumonia.

Your bodily fluids may be tested. This can be done with:

  • Blood tests and/or cultures
  • Sputum culture
  • Urine tests

Pulse oximetry measures blood oxygen levels.

Images may be taken of your lungs. This can be done with:

Treatment

Treatment of pneumonia depends on:

  • What caused the pneumonia
  • Severity of symptoms
  • Other factors, like your overall health

People with severe pneumonia may need to be hospitalized.

Medications

Your doctor may advise:

  • Antibiotics—for pneumonia caused by bacteria
  • Antifungal medications—for pneumonia caused by fungi
  • Antiviral medications—for pneumonia caused viruses, such as influenza
  • Over-the-counter medications to reduce fever and discomfort
  • Vitamin C may be advised if you don't get enough in your diet
  • Oxygen therapy may be needed in more severe cases

It is important to take all medications as prescribed, even when you are feeling well.

Prevention

Certain vaccines may prevent pneumonia:

  • Flu vaccine—pneumonia may be a complication of the flu for people at high risk of infection, especially aged 50 years and older
  • Pneumococcal vaccine:
    • All adults who are aged 65 years or older
    • Adults of any age who are at high risk of infection or have a suppressed immune system

Other preventive measures include:

  • If you smoke, talk to your doctor about how you can successfully quit. Smoke weakens the lungs' resistance to infection and increases recovery time.
  • Avoid close contact with people who have the cold or flu.
  • Wash your hands often, especially after coming into contact with someone who is sick..
  • Protect yourself on jobs that include chemicals or other lung irritants.
  • Maintain good control of any chronic disease, such as asthma and diabetes.

Revision Information

  • American Academy of Family Physicians

    http://www.familydoctor.org

  • American Lung Association

    http://www.lung.org

  • The College of Family Physicians of Canada

    http://www.cfpc.ca

  • The Lung Association

    http://www.lung.ca

  • 2014 Immunization schedules. Centers for Disease Control and Prevention website. Available at: http://www.cdc.gov/vaccines/schedules/easy-to-read/index.html. Updated January 31, 2014. Accessed February 17, 2014.

  • Blasi F, Aliberti S, Pappalettera M, Tarsia P. 100 years of respiratory medicine: pneumonia. Respir Med. 2007;101(5):875-881.

  • Braunwald E, Harrison TR, Fauci AS, et al. Harrison's Principles of Internal Medicine. 17th ed. Columbus, OH: McGraw-Hill; 2008.

  • Carpenter CC, Andreoli TE, Griggs RC. Cecil Essentials of Medicine. Philadelphia, PA: Elsevier Science; 2003.

  • De Roux A, Marcos MA, Garcia E, Mensa J, Ewig S, Lode H, Torres A. Viral community-acquired pneumonia in non-immunocompromised adults. Chest. 2004;125(4):1343-1351.

  • Explore pneumonia. National Heart Lung Blood Institute (NHLBI) website. Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/pnu. Updated March 1, 2011. Accessed February 17, 2014.

  • How can pneumonia be prevented? National Heart Lung Blood Institute (NHLBI) website. Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/pnu/prevention.html. Updated March 1, 2011. Accessed February 17, 2014.

  • Niederman MS. Recent advances in community-acquired pneumonia inpatient and outpatient. Chest. 2007 April;4:1205-15.

  • Niederman MS. Review of treatment guidelines for community-acquired pneumonia. Am J Med. 2004;117:Suppl 3A:51S-57S. Review.

  • Pneumonia in adults. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated November 14, 2013. Accessed February 17, 2014.

  • 10/29/2009 DynaMed Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Hemila H, Louhiala P. Vitamin C for preventing and treating pneumonia. Cochrane Database Syst Rev. 2009;(3):CD005532.

  • 10/21/2013 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Hemilä H, Louhiala P. Vitamin C for preventing and treating pneumonia. Cochrane Database Syst Rev. 2013 Aug 8;8.

  • 3/10/2014 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Su VY, Liu CJ, et al. Sleep apnea and risk of pneumonia: a natoinwide population-based study. CMAJ. 2014 Mar 3.

  • 6/17/2014 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed: Reissig A, Copetti R, et al. Lung ultrasound in the diagnosis and follow-up of community-acquired pneumonia: a prospective, multicenter diagnostic accuracy study. Chest. 2012 Oct;142(4):965-972.