The pleura are 2 thin, moist membranes around the lungs that allow your lungs to expand and contract easily. The inner layer is attached to the lungs. The outer layer is attached to the ribs. Pleural effusion is the buildup of excess fluid in the space between the pleura. The fluid can prevent the lungs from fully opening. This can make it difficult to catch your breath.

Pleural effusion may be watery (transudative) or thick (exudative) based on the cause. Treatment of pleural effusion depends on the condition causing the effusion.

Pleural Effusion

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Effusion is usually caused by disease or injury.

Transudative effusion may be caused by:

  • Heart failure or pericarditis
  • Pulmonary embolism
  • Kidney disease
  • Malnutrition
  • Liver disease
  • Pancreatitis
  • A large shift in body fluids
  • Exudative effusion may be caused by:

  • Pneumonia and other lung infections
  • Rheumatic disease, such as sarcoidosis
  • Anti-inflammatory diseases, such as systemic lupus erythematosus
  • Cancer, especially of the lung, breast, or lymph system
  • Tuberculosis
  • Blood clot formation in the lung
  • Risk Factors

    Factors that may increase your chance of pleural effusion include:

  • Having conditions or diseases listed above
  • Taking certain medications
  • Chest injury or trauma
  • Radiation therapy
  • Surgery, especially involving:     
  • Heart
  • Lungs
  • Abdomen
  • Organ transplantation
  • Symptoms

    Some types of pleural effusion do not cause symptoms. Others cause a variety of symptoms, including:

  • Shortness of breath
  • Shallow breathing
  • Rapid pulse or breathing rate
  • Chest pain
  • Stomach discomfort
  • Cough
  • Coughing up blood
  • Weight loss
  • Fever, chills, or sweating
  • Hiccupping
  • Diagnosis

    You will be asked about your symptoms and medical history. A physical exam will be done. This may include listening to or tapping on your chest. Lung function tests will test your ability to move air in and out of your lungs.

    Some blood tests will be done based on what the doctor thinks it causing the fluid.

    Images of your lungs may be taken with:

  • Chest x-ray
  • Ultrasound
  • CT scan
  • Your doctor may take samples of the fluid or pleura tissue for testing. This may be done with:

  • Thoracentesis
  • Biopsy
  • Thoracoscopy
  • Treatment

    Treatment is usually aimed at treating the underlying cause. This may include medications or surgery.

    If your symptoms are minor, your doctor may choose to monitor you until the effusion is gone.

    To Support Breathing

    If you are having trouble breathing, your doctor may recommend:

  • Breathing treatments—inhaling medication directly to lungs
  • Oxygen therapy
  • Drain the Pleural Effusion

    The pleural effusion may be drained by:

  • Therapeutic thoracentesis—a needle is inserted into the area to withdraw excess fluid.
  • Tube thoracostomy—a tube is placed in the side of your chest to allow fluid to drain. It will be left in place for several days.
  • Seal the Pleural Layers

    The doctor may advise chemical pleurodesis. During this procedure, talc powder or an irritating chemical is injected into the pleural space. This will permanently seal the 2 layers of the pleura together. The seal may help prevent further fluid buildup.

    Radiation therapy may also be used to seal the pleura.


    In severe cases, surgery may be needed. Some of the pleura will be removed during surgery. Suregery options may include:

  • Thoracotomy—traditional, open chest procedure
  • Video-assisted thorascopic surgery (VATS)—minimally-invasive surgery that only requires small keyhole size incisions
  • Prevention

    Prompt treatment for any condition that may lead to effusion is the best way to prevent pleural effusion.