Hyperresonance

Hyperresonance is a descriptor used in physical examination to describe an abnormally loud, low-pitched percussion note over a body region, most often the chest. It indicates increased air content or decreased tissue density within the examined area. In chest auscultation, a hyperresonant percussion note contrasts with a normal resonant sound and with dull notes over fluid- or mass-filled tissues.

Common causes in the chest include pneumothorax (especially large or tension pneumothorax), barrel-shaped hyperinflation from emphysema or other chronic obstructive lung disease, and acute or chronic asthma with air trapping. Large bullae can also produce hyperresonance. Other less common causes include subcutaneous emphysema or technical factors (improper percussion) and variations in body habitus.

Clinical interpretation: Hyperresonance suggests excess air or reduced density but is not specific. It should be interpreted in the context of other findings such as breath sounds, chest expansion, tracheal position, and imaging. It can accompany a clinically significant pneumothorax requiring further evaluation.

Assessment and management: If hyperresonance is detected, clinicians correlate with symptoms and signs; chest radiography or computed tomography is used to confirm pneumothorax or assess lung hyperinflation. The underlying cause guides management, which may range from observation and bronchodilation for COPD-related hyperinflation to urgent decompression in the case of a tension pneumothorax.