Pleural effusion

A pleural effusion is excess fluid that accumulates in the pleural cavity, the fluid-filled space that surrounds the lungs. This excess fluid can impair breathing by limiting the expansion of the lungs. Various kinds of pleural effusion, depending on the nature of the fluid and what caused its entry into the pleural space, are hydrothorax (serous fluid), hemothorax (blood), urinothorax (urine), chylothorax (chyle), or pyothorax (pus) commonly known as pleural empyema. In contrast, a pneumothorax is the accumulation of air in the pleural space, and is commonly called a 'collapsed lung'.Massive left-sided pleural effusion (whiteness) in a patient presenting with lung cancer.CT scan of the chest showing a left-sided pleural effusion. The fluid usually settles at the lowest space due to gravity; in this case, at the back because the patient is supine.The lung expanding within an area of pleural effusion as seen by ultrasoundMicrograph of a pleural fluid cytopathology specimen showing malignant mesothelioma, one cause of a pleural effusion.A pleural effusion as seen on lateral upright chest x rayPleural effusion as seen behind the heart.Massive pleural effusion, later proven to be hemothorax in a South Indian male. A pleural effusion is excess fluid that accumulates in the pleural cavity, the fluid-filled space that surrounds the lungs. This excess fluid can impair breathing by limiting the expansion of the lungs. Various kinds of pleural effusion, depending on the nature of the fluid and what caused its entry into the pleural space, are hydrothorax (serous fluid), hemothorax (blood), urinothorax (urine), chylothorax (chyle), or pyothorax (pus) commonly known as pleural empyema. In contrast, a pneumothorax is the accumulation of air in the pleural space, and is commonly called a 'collapsed lung'.