Picture of Pneumothorax
Pneumothorax is a condition that results when air gets into the chest wall and the lung collapses. A pneumothorax may occur due to an injury (broken rib, trauma to the chest wall, etc.), smoking, lung disease (asthma, COPD, others), and sometimes even spontaneously.
Pneumothorax is treated by placing a tube into the chest wall to evacuate the air. This allows the lung to expand. If a pneumothorax is sufficiently small, it may resolve on its own without treatment.
Text Reference: Pleural Diseases: "Physiological Effects of Pneumothorax and Pleural Effusion"