What is pleural effusion?

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

How does it occur?

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

Conditions that produce thin fluid are:

• congestive heart failure

• salt retention, which causes swelling

• tumor

• body function readjustment, or readjustment after childbirth

• cardiac bypass graft surgery.

Conditions that produce thick fluid include:

• bacterial pneumonia

• lung cancer

• breast cancer

• cancer in the lymph system

• tuberculosis

• rheumatic diseases.

What are the symptoms?

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

• no pain

• possibly shortness of breath.

If the excess fluid is thick the symptoms include:

• chest pain

• possibly shortness of breath

• possibly fever.

How is it diagnosed?

To diagnose pleural effusion, the doctor will ask about your symptoms, look at your medical history, and examine you.

The doctor may order chest x-rays and do a thoracentesis. A thoracentesis is a procedure that is usually done under local anesthesia. It is performed to get a fluid sample from your lungs. During this procedure, the doctor inserts a needle into a space between your ribs and withdraws some fluid. The sample of fluid is sent to a lab for testing.

The doctor may order a biopsy if he or she suspects tuberculosis. During a biopsy, the doctor takes tissue and fluid samples from the pleural cavity. The samples are sent to a lab for testing. By testing the samples, the doctor may discover the cause of your pleural effusion and treat the problem.

How is it treated?

The doctor may treat pleural effusion by immediate removal of the fluid. The doctor can remove the excess fluid by using chest tubes, suction, or other methods. However, the doctor will also want to treat the underlying disease causing the problem.

The doctor may give you medication to take for pain. If you have only minor discomfort, you may leave the hospital. Usually, you stay in the hospital if any of the following occur:

• there is pus in the fluid

• there is a pocket of pus in the pleural cavity

• you have intense, rapid breathing that begins abruptly and then stops after a short time

• you have a lot of discomfort.

You are also hospitalized if any of the following are likely:

• a clot blocking blood vessels (embolism)

• severe congestive heart failure

• lung inflammation (pneumonitis).

Surgery may be necessary.

How can I prevent pleural effusion from occurring?

You can reduce or prevent pleural effusion by early diagnosis and treatment of the underlying condition. See the doctor immediately if you have symptoms such as chest pain or difficulty in breathing.