Which patient profile is most commonly associated with spontaneous pneumothorax?

• A. Tall, thin young male
• B. Older female with asthma
• C. Child with croup
• D. Obese male with COPD

Answer: (A)

Spontaneous pneumothorax most commonly occurs in tall, thin young men because rupture of small air blisters (blebs) on the lung surface at the apex is more likely in this body habitus. The vertical shape of the chest in these individuals leads to higher apical pleural pressure and a predisposition for bleb formation and rupture, allowing air to leak into the pleural space and collapse the lung. This situation is typical of a primary spontaneous pneumothorax, where there is no underlying lung disease driving the event.

In contrast, an older woman with asthma points to a secondary spontaneous pneumothorax related to underlying lung pathology that’s more common with age and chronic disease. A child with croup involves viral airway inflammation, not a spontaneous air leak. An obese man with COPD has increased risk from chronic lung disease, but the classic teaching point for spontaneous pneumothorax—the one most commonly seen in practice—is the tall, thin young man with a primary event.