There are two types of pneumothorax: traumatic and atraumatic. Air can enter the pleural space by two mechanisms, either by trauma causing communication through the chest wall or from the lung by rupture of the visceral pleura.
The degree of collapse determines the clinical presentation of pneumothorax. The air accumulation can apply pressure on the lung and make it collapse. It occurs when air accumulates between the parietal and visceral pleurae inside the chest. A pneumothorax is a collection of air outside the lung but within the pleural cavity.
