Whats the cause of a pnuemothorax?

Pneumothorax: Blunt or penetrating chest injuries can result in pneumothoracies. Underlying lung disease like emphysema (COPD), cystic fibrosis or pneumonia. Blebs that rupture ("air blisters" that can develop on the tops of lungs) can also cause this trauma. Mechanical ventilation while in and of itself life saving can cause pressure differences in the lung causing the rupture as well.

Several causes:: Infection, trauma, and cancer can all cause a pneumothorax (collapsed lung). Sometimes it happens r no reason, especially in smokers who are thin.