Pulmonary Atelectasis

**Definition:** Absence of air in the entire or part of a lung, such as an incompletely inflated neonate lung or a collapsed adult lung. Pulmonary atelectasis can be caused by airway obstruction, lung compression, fibrotic contraction, or other factors.

**Tree numbers:** - C08.381.730

**Synonyms:** - Atelectasis - Lung Collapse