Pleural Effusion: Symptoms, Causes, Diagnosis & Treatment

Pleural effusion, also called “water on the lungs”, is an unusual amount of fluid buildup in the area between your lungs and the chest cavity. It may result from numerous health conditions such as pneumonia. In certain cases, it can also be fatal. 

Pleural effusion can resemble a respiratory infection. The underlying cause is sometimes respiratory, but there are various other potential causes as well. Your healthcare provider will first need to identify the root cause before prescribing the suitable pleural effusion treatment. 

The pleura refers to thin membranes that cover the outside of the lungs and the inside of the chest cavity and facilitate breathing. When you have pleural effusion, fluid builds up in the space between the layers of your pleura. Usually, only a small amount of fluid is present inside the pleura that allows your lungs to move freely in your chest cavity when you breathe. 

What Causes Pleural Effusion?

Pleural effusions are very prevalent in the United States, with nearly 100,000 cases diagnosed each year. Based on the underlying cause, the excess fluid can be either protein-poor (Transudative) or protein-rich (Exudative). These two types help doctors determine the cause of the pleural effusion.

The most common causes of transudative pleural effusions include:

  • Heart failure
  • Cirrhosis
  • Pulmonary embolism
  • Post open heart surgery

Exudative pleural effusions are commonly caused due to:

  • Pneumonia
  • Pulmonary embolism
  • Kidney disease
  • Cancer
  • Inflammatory disease

Other less common causes of pulmonary effusions include:

  • Tuberculosis
  • Bleeding (due to chest trauma)
  • Autoimmune disease
  • Asbestos pleural effusion (caused due to exposure to asbestos)
  • Ovarian hyperstimulation syndrome
  • Meigs syndrome (due to a benign ovarian tumor)
  • Rare chest and abdominal infections
  • Chylothorax (due to trauma)

Abdominal surgery, radiation therapy, and certain medications can also cause pulmonary effusions. Pleural effusion may also occur with various types of cancer, including breast cancer, lung cancer, and lymphoma. In certain cases, the fluid itself may be cancerous (malignant) or maybe a direct consequence of cancer therapy. 

What Are The Symptoms Of Pleural Effusion?

Some people exhibit no symptoms of pleural effusion. These people generally find out they have the condition through physical examinations or chest X-rays done for another reason.

Some common symptoms of pleural effusion include:

  • Dry cough
  • Chest pain
  • Shortness of breath
  • Persistent hiccups
  • Difficulty breathing when lying down
  • Fever
  • Difficulty taking deep breaths
  • Difficulty doing physical activity

Consult your healthcare provider immediately if you experience any symptoms of pleural effusion.

What Are The Types Of Pleural Effusion?

There are two types of pleural effusion, including:

Transudative: This pleural effusion fluid is comparable to the fluid you typically have in your pleural space. It forms from the liquid leaking across the normal pleura. This type hardly needs to be drained unless it’s too large. Congestive heart failure is one of the most common cause of this type.

Exudative: This forms from extra fluid, blood, protein, inflammatory cells, or often bacteria that leak across damaged blood vessels into the pleura. You might need to get it drained, depending on its size and the inflammation caused. 

How Is Pleural Effusion Diagnosed?

Following tests are usually used to diagnose pleural effusion:

  • Chest x-ray
  • Ultrasound of the chest
  • Computed tomography (CT) scan of the chest
  • Thoracentesis (in this procedure, a needle is inserted between your ribs to extract a biopsy or small sample of fluid)
  • Pleural fluid analysis (an analysis of the fluid withdrawn from the pleural space)

If your doctor discovers you have a pleural effusion but were unable to diagnose which type, they may schedule a thoracoscopy. This is a surgical procedure that allows your doctor to view the inside of your chest cavity with a fiber-optic camera. 

For this procedure, your healthcare provider will make a few cuts or incisions in your chest area while you’re under general anesthesia. Then, they will insert the surgical tool from one incision and the camera from the other to draw a small amount of fluid for analysis.

How Is Pleural Effusion Treated?

Pleural effusion can be treated in the following ways:

Draining of fluid

The treatment involved draining the fluid from the chest cavity, either by means of a needle or a tube inserted into the chest. 

You’ll be given local anesthesia, which will make the treatment more comfortable for you. You can feel a little pain or discomfort at the incision site after the effects of the anesthetic wear off. You may need to undergo this treatment multiple times if the fluid builds up again.

Other pleural effusion treatments may be necessary if cancer is the underlying cause of the condition. 


In this procedure, a special chemical called a sclerosant is injected into the pleural space. This causes inflammation of the pleural membranes and helps them bind together. This helps to prevent fluid from building up again into an effusion. Some commonly used sclerosing chemicals include sterile talc, tetracycline, and bleomycin. Pleurodesis is mostly used in the treatment of repeated (recurrent) effusions caused by cancer.


In more severe cases, a doctor surgically inserts a small tube into the chest cavity. This helps direct the fluid from the chest into the abdomen, where it could be easily expelled from the body. This may be a suitable pleural effusion treatment for those who don’t respond to any other treatments. Pleurectomy, in which a part of the pleural lining is surgically removed, can also be a viable option in certain cases.

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Janet Fudge

Janet Fudge writes on general health topics for She holds a post-graduate diploma in Public Health with a major in epidemiology. During the outbreak of COVID-19, Janet actively volunteered in vaccination drives throughout the state of Iowa. She lives in Iowa with her husband and two children.