Which auscultation finding is most consistent with a pneumothorax?

• A. Normal breath sounds bilaterally
• B. Diminished breath sounds on one side
• C. Harsh crackles at the bases
• D. Wheezes throughout the lungs

Answer: (B)

When air leaks into the pleural space, the affected lung can partially or fully collapse, reducing ventilation on that side. That drop in airflow makes breath sounds softer or absent over the side with the pneumothorax. Among the options, diminished breath sounds on one side best matches this scenario because it reflects the loss of lung inflation on the troubled side.

Normal breath sounds on both sides would not fit a pneumothorax, since at least the side with the collapsed lung typically loses audible air sounds. Harsh crackles at the bases suggest fluid or atelectasis rather than a pneumothorax, and wheezes throughout the lungs point to airway constriction or obstruction, not the collapse of a lung.