A pneumothorax can be caused by a blunt or penetrating chest injury, certain medical procedures involving the lungs or due to underlying lung disease. Sometimes, pneumothorax occurs for no obvious reason. When the lung collapses, it causes sudden chest pain and shortness of breath.

A pneumothorax can be caused by a blunt or penetrating chest injury, certain medical procedures involving the lungs or due to underlying lung disease. Sometimes, pneumothorax occurs for no obvious reason. When the lung collapses, it causes sudden chest pain and shortness of breath.