What happens during obstructed atelectasis?

Obstructed atelectasis occurs when an airway is blocked, leading to the collapse of the associated lung tissue. When an airway is obstructed—whether due to a foreign body, mucus plug, tumor, or other factors—the normal airflow to that segment of the lung is cut off.

As a result of this obstruction, the air that was previously present in the alveoli begins to be reabsorbed into the bloodstream, leaving the alveoli empty. This process causes the lung tissue to collapse because there is no longer sufficient air pressure to keep the alveoli open. The loss of volume in the lung segment reduces oxygenation and can cause respiratory distress.

This condition contrasts with situations where the pleura or spaces around the lung become inflamed or where fluid accumulates due to other pathology, which do not directly lead to the specific mechanism of airway obstruction and subsequent lung collapse characteristic of obstructed atelectasis. Understanding this pathology is critical for diagnosing and managing respiratory issues effectively.