Absent lung sounds are an indication of which condition?

• A. Pneumothorax
• B. Atelectasis
• C. Pneumonia
• D. Pericardial tamponade

Answer: (A)

When air leaks into the pleural space, the lung on that side collapses, so auscultation over the affected area shows little to no breath sounds. This absence is a hallmark finding for pneumothorax, especially with sudden shortness of breath or chest trauma.

Atelectasis can also reduce breath sounds but is often not completely silent and may be accompanied by dullness to percussion or other signs. Pneumonia usually produces crackles or other abnormal sounds rather than absent breath sounds. Pericardial tamponade mainly affects the heart and often presents with muffled heart sounds and hemodynamic signs, with lung sounds that may still be present.