Which statement about simple pneumothorax is true?

• A. Heals on its own without any treatment.
• B. Is commonly caused by blunt chest trauma.
• C. Often has a nontraumatic cause.
• D. Is caused by penetrating chest trauma.

Answer: (B)

Simple pneumothorax is a small amount of air in the pleural space without the signs of a tension pneumothorax. A common way this can occur is from blunt chest trauma, where the impact can tear the lung or pleura and let air leak into the space, creating a small, non-urgent pneumothorax. This makes blunt trauma a frequent mechanism behind a simple pneumothorax, which is why that statement is the best choice.

The other ideas aren’t as consistently true. Some simple pneumothoraces resolve with observation, but others require monitoring or intervention, so it isn’t guaranteed to heal on its own. While spontaneous (nontraumatic) causes do exist, they are not as universally linked to “simple” pneumothorax as blunt trauma is to traumatic cases. Penetrating trauma can cause pneumothorax too, but it often leads to larger or more complex injuries and isn’t the typical description of a simple pneumothorax.