Atelectasis is an abnormal condition characterized by the collapse of lung tissue, preventing the respiratory exchange of carbon dioxide and oxygen.

Atelectasis - a collapsed or airless state of the lung - may be acute or chronic, and may involve all or part of the lung.

The primary cause of atelectasis is obstruction of the bronchus serving the affected area.

This condition may be caused by obstruction of the major airways and bronchioles, by pressure on the lung from fluid or air in the pleural...