A ruptured lung can occur spontaneously or due to trauma. Spontaneous pneumos happen in thin, lanky young males, or patients with underlying lung disease.
A pneumothorax presents with acute onset pleuritic chest pain. There may be dyspnea, though I had one young healthy man with a totally collapsed lung who denied shortness of breath. Physical exam reveals unilaterally decreased or absent breath sounds, resonant to percussion.
A chest x-ray makes the diagnosis. Small pneumothoraces (which don’t require chest tubes) may require an x-ray in full expiration.
See posting Chest Pain – 2.