Hemothorax is defined as what?

• A. Air in the pleural space
• B. Blood in the pleural space
• C. Pus in the pleural space
• D. Lymph in the pleural space

Answer: (D)

Blood in the pleural space defines a hemothorax. The pleural space is the thin gap between the lung surface and chest wall; normally it contains only a small amount of fluid. When blood accumulates there, it usually results from trauma, fracture to the ribs, surgical injury, or bleeding disorders. The collected blood can compress the lung, limit its expansion, and reduce gas exchange, which may lead to shortness of breath and hypoxia. Clinically you might see chest pain, rapid heart rate, decreased breath sounds on the affected side, and dullness to percussion. Imaging—such as chest X-ray or CT—often shows a layering fluid level on the affected side, and ultrasound can help detect bleeding quickly. It’s helpful to contrast this with pneumothorax (air in the pleural space), empyema (pus in the pleural space), and chylothorax (lymph in the pleural space).