Atelectasis is the complete or partial collapse of a lung or lobe of a lung, according to Mayo Clinic. The term does not specify how much of the lung has collapsed. Mild dependent atelectasis refers to small areas of the lung near the spine that do not fully expand when a person is lying down, states NetWellness. This condition usually does not require treatment, as the lung inflates normally when the person is sitting or standing up.
Atelectasis can develop due to a blocked airway or pressure from outside of the lung, explains Mayo Clinic. Most people who have surgery experience some atelectasis after the surgery. This is due to the fact that anesthesia changes the normal pattern of breathing and absorption of gases, which can cause the collapse of some of the tiny air sacs in the lung.
Mucus plugs, inhaled foreign objects and blood clots can cause obstructive atelectasis. Nonobstructive atelectasis can be the result of chest trauma, pneumonia and certain tumors, reports Mayo Clinic. Treatment for many occurrences of atelectasis involves loosening mucus in the lungs, performing deep breathing exercises and removing obstructions by bronchoscopy, according to MedlinePlus. Doctors resolve other occurrences by treating the underlying cause, such as a blood clot or tumor.