What is the typical cause of a spontaneous pneumothorax?

• A. Major trauma to the chest
• B. Weak area on the lung rupturing without significant injury
• C. Infection leading to lung collapse
• D. Blockage of airway passages

Answer: (B)

A spontaneous pneumothorax typically occurs when there is a rupture of a weak area in the lung, often called a bleb, that happens without any significant external trauma. This condition is more commonly seen in young, tall males and may occur suddenly and without warning. The rupture allows air to escape from the lung into the pleural space, leading to lung collapse on that side.

The nature of this condition differentiates it from other types of pneumothorax, such as those caused by major trauma or pre-existing pulmonary pathology. Major trauma usually results in a tension pneumothorax or traumatic pneumothorax, where external forces are the primary cause. Similarly, infections and blockages of the airway tend to lead to other lung complications that are distinct from the sudden and idiopathic occurrence of a spontaneous pneumothorax. This highlights the uniqueness of the spontaneous pneumothorax and supports why a weak area on the lung rupturing without significant injury is the typical cause.