Absent breath sounds on one side after trauma most likely indicates which condition?

• A. Pneumothorax
• B. Hemothorax
• C. Pulmonary edema
• D. Atelectasis

Answer: (A)

Unilateral absent breath sounds after trauma point to pneumothorax, where air has entered the pleural space and causes that lung to collapse. With the lung partially or completely not expanding, sound transmission is lost on that side, which is a classic sign of a pneumothorax.

Hemothorax can also reduce breath sounds, but you’d typically expect dullness to percussion and signs of fluid in the chest rather than a complete absence of sounds. Pulmonary edema usually presents with bilateral crackles and is not an acute unilateral trauma finding. Atelectasis can dull or decrease breath sounds as the alveoli collapse, but it often relates to airway obstruction or postoperative states and isn’t as immediately linked to unilateral trauma as pneumothorax.