Pneumothorax Definition & Overview

Definition

Pneumothorax is a condition in which air or gas collects in the "pleural space" or "pleural cavity," which is the space between the lungs and the chest cavity. This can cause the lung to collapse.

Normally, the lungs sit next to the inner surface of the chest wall. Thin membranes called pleura cover both the lungs and the chest wall. A pneumothorax occurs when air either escapes the lung or leaks in through the chest wall and builds up in the pleural space between them. This build-up of air can result in the collapse of the affected lung.

There are different types of pneumothorax, and each one is defined by its cause.