Pneumothorax is a possible complication of pneumomediastinum. This is because the trapped air in the mediastinum can accumulate in the pleural space around the lungs, causing one or both lungs to collapse.
A collapsed lung may be minor or severe. Possible symptoms include:
sharp, stabbing chest pain that worsens during inhalation
shortness of breath
rapid breathing
rapid heartbeat
dry, hacking cough
fatigue
bluish skin discoloration due to a lack of oxygen
Anyone who experiences severe or worsening symptoms of a collapsed lung should seek emergency medical attention.