In a tall, thin patient with sudden chest pain, which exam finding would most strongly suggest spontaneous pneumothorax?

• A. Diminished breath sounds on the affected side
• B. Hyper-resonant percussion on both sides
• C. Bilateral crackles
• D. Normal breath sounds

Answer: (A)

Air in the pleural space causes the lung to collapse, which reduces the transmission of sound to the stethoscope. This leads to diminished breath sounds on the side of the pneumothorax, making it the most telling exam finding. In spontaneous cases, especially in a tall, thin patient, the problem is often unilateral, so this unilateral decrease in sounds is a strong clue.

Hyper-resonance can accompany pneumothorax because the chest cavity contains more air, but it’s usually one-sided and not as specific as the loss of breath sounds. Bilateral crackles don’t fit pneumothorax, and normal breath sounds would argue against it.