Which term describes the presence of blood in the pleural space?

• A. Hemothorax
• B. Hemopneumothorax
• C. Pneumothorax
• D. Pleural effusion

Answer: (A)

The presence of blood in the pleural space is called a hemothorax. The pleural space lies between the lung and the chest wall, and normally contains only a small amount of lubricating fluid. When blood collects there, usually from chest trauma or vessel injury, it can compress the lung and hinder expansion, leading to breathing difficulties and possible shock if the bleed is large. This is distinct from pneumothorax, where air is in the pleural space; from hemopneumothorax, where both air and blood are present; and from pleural effusion, which is any fluid in the space (not necessarily blood).