Pleural Effusion

What is pleural effusion?

Pleural effusion is the buildup of excess fluid in the space between the lungs and the ribcage. Pleural effusion prevents the lungs from fully expanding during breathing.

What is the cause?

The space between the lungs and the ribcage is the pleural cavity. Normally, there is a small amount of fluid in this space that acts as a lubricant and allows the lungs to expand smoothly during breathing. When there is too much fluid, the lungs cannot expand as well. Some conditions can cause excess fluid to build up in the pleural cavity. The excess fluid is either thin, almost like water, or thick, like pus.

Conditions that produce thin fluid are:

• heart failure
• salt retention, which causes swelling
• tumor, such as a tumor of the lung, breast, or ovary
• a big change in body fluids, such as after childbirth
• cardiac bypass graft surgery

Conditions that produce thick fluid include:

• bacterial pneumonia
• lung cancer, breast cancer, or cancer in the lymph system
• tuberculosis
• rheumatic diseases

What are the symptoms?

If the excess fluid is thin and watery, the symptoms may include:

• no pain
• shortness of breath

If the excess fluid is thick, the symptoms may include:

• chest pain
• shortness of breath
• fever

How is it diagnosed?

Your healthcare provider will ask about your symptoms, look at your medical history, and examine you.

Your provider may order chest X-rays. You may need a thoracentesis. A thoracentesis is a procedure that can be done to get a fluid sample from your lungs. After numbing the area, your healthcare provider inserts a needle through a space between your ribs and draws out some fluid. The sample of fluid is sent to a lab for testing.

Your healthcare provider may order a biopsy if he or she thinks you may have tuberculosis or a tumor. For a biopsy, your provider takes samples of fluid and tissue from the lung. This can usually be done in a way similar to how the thoracentesis is done. The samples are sent to a lab for tests.

How is it treated?

Your healthcare provider may treat symptoms caused by pleural effusion by immediate removal of the fluid. Your provider can remove the excess fluid with chest tubes, suction, or other methods. When the results of all the tests are available, your provider will also treat the underlying disease causing the fluid buildup.

Your provider may give you pain medicine. If you have only minor discomfort, you may leave the hospital. Usually, you will stay in the hospital if any of the following happen:

• There is pus in the fluid.
• There is a pocket of pus in the lung cavity (an abscess).
• You have trouble breathing.
• You have a lot of discomfort.

You will also stay at the hospital if any of the following are likely:

• a blood clot (embolism)
• severe heart failure
• lung inflammation (pneumonitis)

In some cases you may need surgery.

How can I prevent pleural effusion from occurring?

Most pleural effusions cannot be prevented. Some pleural effusion may be prevented by early diagnosis and treatment of the underlying condition.