Excess fluid accumulating in the pleural cavity.Encyclopedia Entry for Pleural Effusion :Pleural effusion. The body produces pleural fluid in small amounts to lubricate the surfaces of the pleura. This is the thin tissue that lines the chest cavity and surrounds the lungs. Pleural effusion is an abnormal, excessive collection of this fluid. There are two types of pleural effusion: Transudative pleural effusion is caused by fluid leaking into the pleural space. This is from increased pressure in the blood vessels or a low blood protein count. Heart failure is the most common cause. Exudative effusion is caused by blocked blood vessels or lymph vessels, inflammation, lung injury, and tumors. Risk factors of pleural effusion may include: Smoking and drinking alcohol Any previous complaint of high blood pressure History of any contact with asbestos.Symptoms can include any of the following: Chest pain , usually a sharp pain that is worse with cough or deep breaths Cough Fever and chills Hiccups Rapid breathing Shortness of breath Sometimes there are no symptoms.Your health care provider will examine you and ask about your symptoms. The provider will also listen to your lungs with a stethoscope and tap (percuss) your chest and upper back. Chest CT scan or a chest x-ray may be enough for your provider to decide on treatment. Your provider may want to perform tests on the fluid. If so, a sample of fluid is removed with a needle inserted between the ribs. Tests on the fluid will be done to look for: Infection Cancer cells Protein levels Blood tests that may be done include Complete blood count (CBC), to check for signs of infection or anemia Kidney and liver function blood tests If needed, these other tests may be done: Ultrasound of the heart (echocardiogram) to look for heart failure Lung biopsy to look for cancer Passing a tube through the windpipe to check the airways for problems or cancer ( bronchoscopy ).The goal of treatment is to: Remove the fluid Prevent fluid from building up again Determine and treat the cause of the fluid buildup Removing the fluid (thoracentesis) may be done if there is a lot of fluid and it is causing chest pressure, shortness of breath, or a low oxygen level. Removing the fluid allows the lung to expand, making breathing easier. The cause of the fluid buildup must also be treated: If it is due to heart failure, you may receive diuretics (water pills) and other medicines to treat heart failure. If it is due to an infection, antibiotics will be given. In people with cancer or infection, the effusion is often treated by using a chest tube to drain the fluid. In some cases, any of the following treatments are done: Chemotherapy Placing medicine into the chest that prevents fluid from building up again after it is drained Radiation therapy Surgery.The outcome depends on the underlying disease.Complications of pleural effusion may include: Lung damage Infection that turns into an abscess, called an empyema Air in the chest cavity ( pneumothorax ) after drainage of the effusion Pleural thickening (scarring of the lining of the lung).Call your provider or go to the emergency room if you have: Symptoms of pleural effusion Shortness of breath or difficulty breathing right after thoracentesis.Fluid in the chest; Fluid on the lung; Pleural fluid.Lungs Lungs Respiratory system Respiratory system Pleural cavity Pleural cavity.Broaddus VC, Light RW. Pleural effusion.