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Pneumonia

Pneumonia is a lung infection that can range from mild to life-threatening. It is commonly caused by bacterial or viral infections but can sometimes be due to fungal infections or aspirating (inhaling) a substance into the lungs. Pneumonia leads to airway inflammation and the alveoli (air sacs) may fill with fluid. Some cases will cause a problem in one lobe (segment) of one lung, while serious cases can affect all five lobes.

Viral pneumonia can be due to flu, respiratory syncytial virus (RSV), or COVID-19. Bacterial pneumonia is often due to Streptococcus pneumoniae and referred to as pneumococcal pneumonia.

Treatments may include prescription or over-the-counter (OTC) medications and breathing treatments. In severe cases, hospitalization may be necessary.

Frequently Asked Questions

  • Is pneumonia contagious?

    Viruses and certain bacteria that can lead to pneumonia are contagious and infections can occur after coming into contact with someone who is infected or touching contaminated surfaces. Bacterial infections can also occur after the immune system is weakened due to illnesses. Anyone can get pneumonia, but children under age 2 and adults over age 65 have an increased risk of severe infections.

  • How do you get pneumonia?

    There are four types: 

    • Community-acquired pneumonia develops from infections picked up outside of healthcare settings.
    • Healthcare-associated pneumonia develops in a healthcare setting, such as a hospital, long-term care facility, or clinic. 
    • Ventilator-associated pneumonia is when germs enter a ventilator tube. 
    • Aspiration pneumonia is due to food, drink, gum, vomit, or saliva inhaled into the lungs.
  • What does pneumonia feel like?

    Pneumonia leads to a severe cough in many cases. This is your body's way of trying to clear out sputum (a pus-like mixture of saliva and mucus) that collects in the alveoli of the lungs. It can also cause symptoms such as fever, shortness of breath, chest pain, body aches, vomiting, weakness, and feeling confused.

  • How do you treat pneumonia?

    Treatment varies based on the cause of the infection and severity of symptoms. It may include antibiotics (bacterial pneumonia), antivirals (viral pneumonia), or antifungals (fungal pneumonia). There may also be over-the-counter medications or supplemental oxygen. Plenty of rest and fluids is recommended. Severe cases may require hospitalization and the use of a ventilator, but this is uncommon.

  • What is walking pneumonia?

    The bacteria Mycoplasma pneumoniae causes an infection commonly referred to as walking pneumonia. It’s called this because it often has mild symptoms and typically responds well to antibiotics. Walking pneumonia is a form of community-acquired pneumonia that spreads in crowded environments, such as dormitories or daycares.

  • How long does pneumonia last?

    Recovery from pneumonia can range from one week to a month or more. Your doctor may want to see you for follow-up appointments and may do tests, such as chest X-rays to check for fluid in your lungs. If your symptoms start to improve and then get worse, contact your physician. This can be a sign that your infection isn’t responding to medication or that you’ve developed another infection.

Key Terms

Page Sources
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  1. Centers for Disease Control and Prevention. Causes of Pneumonia. Updated October 22, 2020.

  2. Almirall J, Serra-prat M, Bolíbar I, Balasso V. Risk factors for community-acquired pneumonia in adults: a systematic review of observational studies. Respiration. 2017;94(3):299-311. doi:10.1159/000479089

  3. Komiya K, Ishii H, Kadota J. Healthcare-associated pneumonia and aspiration pneumonia. Aging Dis. 2014;6(1):27–37. doi:10.14336/AD.2014.0127

  4. Mantero M, Tarsia P, Gramegna A, Henchi S, Vanoni N, Di Pasquale M. Antibiotic therapy, supportive treatment and management of immunomodulation-inflammation response in community acquired pneumonia: review of recommendations. Multidiscip Respir Med. 2017;12:26. doi:10.1186/s40248-017-0106-3

  5. Vold ML, Aasebø U, Wilsgaard T, Melbye H. Low oxygen saturation and mortality in an adult cohort: the Tromsø study. BMC Pulm Med. 2015;15:9. Published 2015 Feb 12. doi:10.1186/s12890-015-0003-5

Additional Reading