While hyperresonance is a common symptom of COPD, it can also indicate another serious respiratory condition known as pneumothorax.
The space between the lungs and chest wall is usually hollow. In the case of pneumothorax, also known as a collapsed lung, air fills that space and puts pressure on one or both lungs.
A person having an asthma attack may also produce hyperresonance with chest percussion. Their lungs become hyperinflated as exhaling becomes more difficult.