what's the most common cause of undiagnosed pleural effusion exudative
Pleural fluids have traditionally been divided into two types: transudative and exudative. The most common causes of transudative pleural effusion are congestive heart failure and cirrhosis. Common causes of exudative pleural effusion include malignancy, pneumonia, pulmonary embolism and viral infection. One study found that 42% of all exudative effusions were due to malignancy, and another found that malignancy was the underlying cause of 24% of all effusions.