Which type of pneumothorax occurs without known cause or injury, resulting in spontaneous lung deflation?

• A. Spontaneous pneumothorax
• B. Tension pneumothorax
• C. Pleural effusion
• D. Hemothorax

Answer: (A)

The described concept is spontaneous pneumothorax. It occurs when air enters the pleural space and the lung collapses without any injury or obvious cause. This often results from rupture of small air sacs (blebs) on the lung surface. It can happen in otherwise healthy people, especially tall, thin individuals or smokers, and is categorized as primary or secondary based on the presence of underlying lung disease. This is distinct from a tension pneumothorax, where air accumulates under pressure and pushes the mediastinum, leading to serious hemodynamic problems that require immediate intervention. Pleural effusion is fluid in the pleural space, and hemothorax is blood in the pleural space, neither of which describes air leaking and causing spontaneous lung deflation.