The Process of Diagnosing and Treating Fluid in the Lungs

Causes. The most common causes of pleural effusion are fluids leaking in from other organs. Kidney, liver, or heart disease and cancers can all be factors. Lung cancer is the most common cancerous cause but other cancers may spread to the lungs. Infections such as tuberculosis and pneumonia and conditions such as Lupus and rheumatoid arthritis are also common causes. A blocked artery in the lung or an injury to the lung may also lead to pleural effusion.