No Pneumothorax Meaning. Pneumothorax occurs when air gains access to, and accumulates in, the pleural space. The buildup of air or gas can put pressure on the lung and cause all or part of it to collapse.

A pneumothorax is an accumulation of air or gas in the space between the lung and the chest wall that occurs when a hole. A pneumothorax is when air gets inside your chest cavity and creates pressure against your lung, causing it to collapse partially or fully.