An x-ray of atelectasis of the right lung. Photograph: Valencia Institute of Oncology
"Atelectasis" - Collapse of part or all of a lung caused by obstruction of one or more air passages in the lung. Obstruction may be caused by accumulation of mucus, by an accidentally inhaled foreign body, by a tumour in the lung, or by enlarged lymph nodes exerting pressure on the airway.
The main symptom is shortness of breath. There may also be a cough and chest pain. The condition can be diagnosed by chest x-ray. Treatment is aimed at removing the cause of the blockage and may include physiotherapy or bronchoscopy. If the obstruction can be removed, the lung should reinflate normally.
"atelectasis". British Medical Association (2007). Illustrated Medical Dictionary. 2nd ed. London: Dorling Kindersley (DK). p56.