by EBSCO Medical Review Board
(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 is usually disease or injury. Common causes are:

Risk Factors

Things that may raise the risk of this problem 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. Others may have:

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


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

A lung function tests will be done. It can show 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:


Treatment depends on what is causing the problem. It may include:

  • Monitoring 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.


Manage health problems that may lead to effusion.


American Lung Association 

National Heart, Lung, and Blood Institute 


Health Canada 

The Lung Association 


Pleural effusion. EBSCO DynaMed website. Available at: Accessed November 25, 2020.

Pleural effusion. Merck Manual Professional Version website. Available at: Accessed November 25, 2020.

Saguil A, Wyrick K, et al. Diagnostic approach to pleural effusion. Am Fam Physician. 2014 Jul 15;90(2):99-104.

Revision Information

  • Reviewer: EBSCO Medical Review Board Marcin Chwistek, MD
  • Review Date: 09/2020
  • Update Date: 04/23/2021