In a spontaneous pneumothorax, which exam finding is most consistent?

• A. Bilateral dullness to percussion
• B. Unilateral diminished breath sounds
• C. Bilateral hyperresonance with increased fremitus
• D. Clear breath sounds on both sides

Answer: (B)

Spontaneous pneumothorax introduces air into the pleural space on one side, causing the lung to collapse there. This reduces the transmission of sound and vibration from that lung, so the exam shows decreased or absent breath sounds on the affected side. The affected side is also typically hyperresonant on percussion and has decreased tactile fremitus, but if you have to pick the single most consistent finding, unilateral diminished breath sounds on the side of the pneumothorax best fits the pattern clinicians expect. The other choices point to fluid or bilateral processes (dullness to percussion) or to findings that don’t match the air in the pleural space (increased fremitus).