UNC Health Care
An elderly man clutches chest with breathing problems

Pleural Effusion: A Common Cause of Shortness of Breath

Shortness of breath is an alarming symptom that can be caused by many conditions, from anxiety and asthma to congestive heart failure. One lesser-known but commonly diagnosed cause is pleural effusion, sometimes called “water on the lungs,” and it can be serious if not treated.

The pleural cavity is the space between the lungs and the chest wall. The pleura are large, thin tissues that line the lungs and chest wall. There’s typically about a teaspoon of fluid in that space to help lubricate the pleura and facilitate breathing.

However, when pleural effusion occurs, this fluid increases.

“Fluid pushes on the chest wall and the diaphragm, your primary breathing muscle, making it a lot harder to breathe,” says UNC Health pulmonologist Jason Akulian, MD, MPH.

More than 1.5 million people in the United States are affected each year by pleural effusion. In the Multidisciplinary Thoracic Oncology Program at UNC Hospitals, nearly half of the interventional pulmonary procedure patients are being treated for pleural effusion, Dr. Akulian says.

The condition indicates an underlying problem or disease, which must be treated to alleviate the pleural effusion.

Symptoms of Pleural Effusion:

The symptoms of pleural effusion may not happen all at once, but they are distinctly noticeable. They include:

  • Shortness of breath
  • Dry cough
  • Chest pressure
  • Chest pain
  • Fever

Dr. Akulian says a vast majority of people with pleural effusion progress to having more than one symptom. People most at risk are those with cancer, pneumonia, infection and age-related comorbidities such as heart failure. Your genetics and lifestyle habits, such as smoking and poor nutrition, also increase risk.

Causes of Pleural Effusion

There are two main types of fluid involved in a pleural effusion: Transudate (bland) or exudate (inflammatory). The type of fluid gives doctors clues on the underlying cause of pleural effusion.

Heart, liver and kidney failure cause transudative pleural effusions. These conditions can all lead to an increase in body water that then gets distributed into the pleural space.

Exudative pleural effusions are caused by an injury or inflammation to the pleura. Cancer and infection are the two main reasons for exudative pleural effusions. The most common cancers of this type include lung and breast cancers and lymphoma.

An infection, such as pneumonia, can lead to inflammation of the lung. This, too, can be a contributing factor to pleural effusion.

Without treatment, pleural effusion can be very serious and even life-threatening. Depending on its severity and its cause, it can lead to a collapsed lung, lung scarring or sepsis (an out-of-control infection). It may indicate progression of the underlying disease.

Treatments for Pleural Effusion

A physical exam, chest X-ray or an ultrasound are the easiest ways to diagnose a pleural effusion. Here are a few of the most common procedures done to help treat pleural effusion.

Thoracentesis: During this procedure, a doctor drains the fluid using a small catheter. This catheter is removed once the procedure is over.

“We drain as much of the fluid as possible. The fluid is then sent to the lab to figure out why it’s there. Once the underlying cause is discovered, such as heart failure or liver failure, we recommend treatment of the underlying condition to decrease the distribution of water into that space,” Dr. Akulian says. This procedure is repeated multiple times if necessary.

Inserting a tunneled pleural catheter: If treatment of the underlying disease is not possible or is taking an extended amount of time, doctors can place a tunneled pleural catheter (a catheter tunneled under the skin to the pleural space). This approach helps to drain fluid safely at home while avoiding prolonged hospitalization.

Chest tube procedure: If doctors are treating an infection at the same time as the pleural effusion, they can insert a small chest tube that will actively drain the fluid during the treatment course. Medication is delivered through the chest tube to try to break up any inflammatory pockets of fluid that may have formed.

To help alleviate symptoms and improve quality of life, doctors use medications to treat the underlying cause of the effusions. If medications and less invasive interventions don’t work, surgery may be necessary, Dr. Akulian says.

Pleural effusion can become a debilitating condition, but with the help of treatments and an early diagnosis, you can recover. The best way to make sure you’re getting the proper treatment is to act fast if you notice changes in your body.

“It’s amazing the degree to which people are willing to accept changes in their body without going to talk with their doctor,” Dr. Akulian says. “We recommend that anyone experiencing the symptoms of pleural effusion seek medical attention sooner rather than later. We can not only make you feel better but look into why it’s there to help treat the underlying condition more effectively.”


If you think you may be experiencing symptoms of pleural effusion, talk with your doctor. If you don’t have one, you can find one here.