Causes of pleural effusion
Pleural effusions are very common, with approximately 100,000 cases diagnosed in the United States each year, according to the National Cancer Institute. Depending on the cause, the excess fluid may be either protein-poor (transudative) or protein-rich (exudative). These two categories help physicians determine the cause of the pleural effusion. The most common causes of transudative (watery fluid) pleural effusions include: Heart failure Pulmonary embolism Cirrhosis Post open heart surgery Exudative (protein-rich fluid) pleural effusions are most commonly caused by: Pneumonia Cancer Pulmonary embolism Kidney disease Inflammatory disease Other less common causes of pleural effusion include: Tuberculosis Autoimmune disease Bleeding (due to chest trauma) Chylothorax (due to trauma) Rare chest and abdominal infections Asbestos pleural effusion (due to exposure to asbestos) Meig’s syndrome (due to a benign ovarian tumor) Ovarian hyperstimulation syndrome