Pleural effusion refers to a condition in which excessive amounts of fluid accumulates in the surrounding regions of the lungs.

The lungs are a pair of spongy, air-filled organs present on either side of the chest. They are encompassed within protective thin membranes called pleura, that cover the inside portions of the chest cavity as well.

In a healthy individual, a small amount of fluid is present in the pleural spaces, to aid in lubricating the lungs, as they expand during breathing. However, in a person with underlying medical conditions, such as heart disease or chest infections like pneumonia, surplus amounts of liquid collects within the hollow pleura, thereby resulting in pleural effusions. Also Read: Chest Infection: Causes, Symptoms And Treatment

Pleural effusion


Various factors give rise to pleural effusions in the lungs. The most common causes are:

  • Congestive heart failures or cardiac conditions resembling them
  • Cirrhosis and similar liver disorders
  • Kidney disease and associated problems
  • Blood clot that obstructs the circulatory vessels in the lungs, known as pulmonary embolism
  • Pneumonia and other serious respiratory ailments
  • Illnesses affecting the immune system, including autoimmune conditions like rheumatoid arthritis
  • Cancer, primarily lung cancer, as well as cancers of bodily organs that metastasize to the lungs


Depending upon the severity of the underlying health anomaly and the relative complexity of treatment procedures, pleural effusions are categorised as either:

  • Transudative And Exudative, Or
  • Complicated And Uncomplicated

Transudative Pleural Effusions:

The fluid overflowing into the pleural cavities in case of transudative effusions, seeps across healthy pleura and is similar in composition and consistency, to the fluid normally present in the cavity around the lungs. It is most often triggered by congestive heart failures and the additional fluid generally does not require to be removed from the lungs.

Exudative Pleural Effusions:

In the case of exudative pleural effusions, leakages from injured blood vessels, such as aberrant proteins, inflammatory tissue remnants and infectious germs like bacteria collect in the pleural cavities. Prompted by inflammation-inducing diseases like pneumonia and lung cancer, the extra fluid surrounding the lungs needs to be drained in this situation. Also Read: Lung Cancer: Causes, Symptoms And Treatment

Complicated Pleural Effusions:

Here, pleural effusions indicate grave signs of infection and inflammation, which, if left untreated, could scar lung tissues to a great extent. Hence immediate medical care is necessary, in order to drain massive fluid content accrued in the chest.

Uncomplicated Pleural Effusions:

In these instances of pleural effusions, infection or inflammation is usually not the causative factor. Hence, the risk of developing serious pulmonary diseases is also very low and these cases do not require advanced medical procedures to rectify the leakage into the pleura.


Minor situations of pleural effusions do not give rise to any distinct symptoms. Only in the case of huge leakages accompanied by infection and inflammation, characteristic indications arise in the individual, which include:

Diagnosis And Treatment

The doctor initially conducts a complete physical exam of the patient, to examine if there are any external signs that indicate problems with the lungs and breathing.

In addition, the medical expert also performs imaging tests, comprising X-rays, ultrasounds and CT scans (computed tomography) of the lungs and chest. These help to visualise the exact spot where the leakage of fluid is taking place, so as to enable precision in treatment methodologies.

Once the precise cause and location of pleural effusions in confirmed in the patient, the doctor initiates the pertinent treatment measures.

Minor cases of pleural effusions only require the underlying disorder to be rectified without any invasive procedures. Examples include situations wherein the health professional prescribes antibiotics if pneumonia is the root cause, or diuretics when the leakages occur due to congestive heart failure.

When the pleural effusion is large, with significant infection or inflammation, advanced protocols are necessary, to drain out the excess fluid situated in the region around the lungs. Common surgical techniques employed to mend the defects in the pleural cavities consist of thoracentesis, tube thoracostomy, pleural drain, pleurodesis and pleural decortication. These ensure the removal of huge fluid pools from the pleural cavities and restore optimal lung function in the patient.