Pleural fluid is secreted by the parietal layer of the pleura and reabsorbed by the lymphatics in the most dependent parts of the parietal pleura, primarily the diaphragmatic and mediastinal regions. Exudative<unk> s occur when the pleura is damaged, e.g., by trauma, infection, or malignancy, and transudative<unk> s develop when there is either excessive production of pleural fluid or the resorption capacity is reduced. Light's criteria can be used to differentiate between exudative and transudative<unk> s.
Pleural effusion
Pleural empyema
Pleurisy
Parapneumonic effusion
Hydrothorax
Pneumothorax
Malignant pleural effusion
Hemothorax