Atelectasis (pronounced at-uh-LEK-tuh-sis) is a term for the partial or complete collapse of the small airways in the lungs. Atelectasis can be due to tumors growing in lung tissue or an airway.

ROME (AP) — Pope Francis has developed pneumonia in both lungs, the Vatican said Tuesday, after new tests showed a further complication in the condition of the 88-year-old pontiff that raised ...