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Pleural Effusion

  • Cynthia M. Johnson, MA
Publication Type:


Pleural Effusion

(Water on the Lungs)


Pleural effusion is a buildup of fluid in the pleura. The pleura are the two thin, moist membranes around the lungs. They let the lungs expand and contract.

Pleural Effusion.

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The cause of pleural effusion is usually disease or injury. Common causes are:

Risk Factors

Things that may raise the risk of pleural effusion are:

  • Having any of the above health problems
  • Taking certain medicines
  • Chest injury
  • Radiation therapy
  • Surgery, especially of the:
    • Heart
    • Lungs
    • Belly
    • Organ transplants


Some people may not have symptoms of pleural effusion. Others may have:

  • Problems breathing
  • Rapid heartbeat
  • Chest or stomach pain
  • Cough
  • Coughing up blood
  • Weight loss
  • Fever or chills
  • Hiccups


The doctor will ask about symptoms and health history. A physical exam will be done. This may include listening to or tapping on the chest.

A lung function test will be done to check how well air is moving in and out of the lungs.

Blood tests may be done based on what the doctor thinks it causing the fluid.

Pictures may be taken of the lungs. This can be done with:

Samples of the fluid or pleura may be taken for testing. This can be done with:


The goal of treating pleural effusion is to reduce the amount of fluid in the pleura. How this is done depends on what is causing the problem. It may include:

  • Watching minor symptoms for any changes
  • Medicine
  • Oxygen therapy
  • Draining the pleural effusion with a needle or placing a tube in the chest to let fluid drain
  • Sealing the pleural layers to prevent more fluid from building up

People who are not helped by other methods may need surgery. Some of the pleura will be removed.


Managing health problems that may lead to pleural effusion could lower the risk of it.





  • Jany, B. and Welte, T. Pleural effusion in adults—etiology, diagnosis, and treatment. Deutsches Ärzteblatt International, 2019; 116 (21): 377-386.
  • Pleural effusion. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/pleural-effusion.
  • Pleural effusion. Merck Manual Professional Version website. Available at: https://www.merckmanuals.com/professional/pulmonary-disorders/mediastinal-and-pleural-disorders/pleural-effusion.


  • Marcin Chwistek, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.