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Pneumonia facts

  • Pneumonia is inflammation of the airspaces in the lungs, most commonly due to an infection.
  • Pneumonia may be caused by viruses, bacteria, or fungi.
  • The most common bacterial type that causes pneumonia is Streptococcus pneumoniae.
  • Signs and symptoms of pneumonia include
  • Community-acquired pneumonia (CAP) is acquired outside of the health-care setting and is typically less severe than hospital-acquired pneumonia (HAP).
  • About 20% of those with CAP require treatment in a hospital.
  • Antibiotics treat pneumonia by controlling the bacterial or fungal infection. The initial choice of antibiotic depends on the organism presumed to be causing the infection as well as local patterns of antibiotic resistance.
  • Pneumonia can be fatal in up to 30% of severe cases that are managed in the intensive-care setting.
  • Complications of pneumonia include sepsis, pleural effusion, and empyema.
  • Influenza and respiratory syncytial virus (RSV) are the most common viral causes of pneumonia.
  • A chest X-ray is typically done to diagnose pneumonia.
  • Risk factors for pneumonia include age over 65 or under 2, having certain chronic medical conditions (including underlying lung disease, cigarette smoking, alcoholism, and neurological problems), or sustaining injuries that interfere with swallowing or coughing.
Medically Reviewed by a Doctor on 5/4/2015

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Is Pneumonia Contagious?

Because pneumonia is caused by microbes, pneumonia can be contagious. Pneumonia caused by chemical fumes or other poisons not made by infectious agents are not contagious.

Many contagious pneumonias have names such as bacterial pneumonia, viral pneumonia, Mycoplasma pneumonia and MRSA (Methicillin-resistant Staphylococcus aureus) pneumonia that indicate the type of pathogen infecting the lung.