Alternate Names: Fluid in the chest; Transudative pleural effusion; Exudative pleural effusion

Causes and Risks:

Pleural fluid is normally formed in small amounts to lubricate the surfaces of the "pleura," the thin membrane that lines the chest cavity and surrounds the lungs. A "pleural effusion" is an abnormal collection of this fluid.

Two different types of effusions can develop. Transudative pleural effusions are usually caused by a disorder in the normal pressure in the lung. Congestive heart failure is the most common type of transudative effusion. Exudative effusions form as a result of inflammation of the pleura, which is often caused by lung disease. Cancer, tuberculosis and other lung infections, drug reactions, asbestosis, and sarcoidosis are some of the diseases that can cause exudative pleural effusions.

The cause and type of pleural effusion can usually be determined by taking a sample of the fluid by thoracentesis (removing fluid through a needle inserted between the ribs into the chest cavity, using a local anesthetic).

Prevention: Most cases are not preventable.

Symptoms:

• Shortness of breath
• Chest pain, usually a sharp pain that is worse with cough or deep breaths
• Cough
• Hiccups
• Breathing, rapid
• Abdominal pain

Note: There may be no symptoms.

Signs and Tests:

Listening to the chest with a stethoscope (auscultation) reveals decreased breath sounds.  Percussion of (tapping on) the chest reveals dullness.

These tests help confirm the diagnosis:

• Chest X-ray
• Thoracic CT
• Ultrasound of the chest
• Thoracentesis
• Pleural fluid analysis

Treatment:

Treatment may be directed at removing the fluid, preventing its reaccumulation, or at the underlying cause of the fluid buildup.

Therapeutic thoracentesis may be done if the fluid collection is large and causing pressure or shortness of breath. In patients with cancer or infections, the effusion is often treated by using a chest tube to drain the fluid.  Chemotherapy, radiation therapy, or instilling medication within the chest that prevents re-accumulation of fluid after drainage may be used. Pleural effusions caused by infection are treated with antibiotics specific to the causative organism.

Prognosis: The expected outcome depends upon the underlying disease.

Complications: A lung surrounded by a fluid collection for a long time can collapse.  Pneumothorax (air within the chest cavity) is a complication of the thoracentesis procedure.

Call your health care provider if symptoms of pleural effusion develop.

Call your health care provider or go to the emergency room if shortness of breath or difficulty breathing occurs immediately after thoracentesis.