A pneumothorax is a collection of free air in the chest outside the lung that causes the lung to collapse, or simply pneumothorax is used to refer to a collapsed lung.
Pneumothorax can occur spontaneously (“out of the blue”, with or without underlying lung disease), follow a fractured rib, occur in the wake of chest surgery, or be deliberately induced in order to collapse the lung. Smoking has been shown to increase the risk for spontaneous pneumothorax.
A small pneumothorax without underlying lung disease may resolve on its own. A larger pneumothorax and a pneumothorax associated with underlying lung disease often require aspiration of the free air and/or placement of a chest tube to evacuate the air. Possible complications of chest tube insertion include pain, infection of the space between the lung and chest wall (the pleural space), hemorrhage (bleeding), fluid accumulation in the lung, and low blood pressure (hypotension).