What does atelectasis mean?
Atelectasis is the medical term for the collapse of part or all of a lung, occurring when the microscopic air sacs known as alveoli lose their air and deflate. Derived from Greek roots meaning 'incomplete stretching,' the word entered English medical usage in the early nineteenth century. Atelectasis has several causes: blockage of an airway (by mucus, a foreign object, or a tumor), pressure on the lung from outside (as with fluid or air in the chest cavity), or shallow breathing — which is why it frequently develops after surgery involving general anesthesia. Many cases cause no symptoms at all and resolve on their own, but extensive collapse can bring shortness of breath, coughing, or low oxygen levels. Clinicians prevent and treat it with deep-breathing exercises, incentive spirometry, chest physiotherapy, and positioning. Though unfamiliar to most laypeople, atelectasis is one of the most common findings on postoperative chest imaging.
nounAtelectasis is the partial or complete collapse of a lung, or of a portion (lobe) of a lung, resulting in reduced or absent air content in the affected tissue. It most commonly occurs when the tiny air sacs (alveoli) deflate, often after surgery or due to airway obstruction.
- The partial or complete collapse of a lung or part of a lung, with loss of air from the alveoli; the condition of imperfect expansion or deflation of pulmonary tissue.
"The chest X-ray revealed atelectasis in the patient's left lower lobe following abdominal surgery."
"Deep-breathing exercises after surgery help prevent atelectasis by keeping the small airways open."
"The CT scan showed subsegmental atelectasis at the base of the right lung, a common incidental finding."
The plural 'atelectases' follows the Greek-style -is → -es pattern but is seldom encountered; writers usually refer to 'areas of atelectasis' or 'foci of atelectasis' instead.
"The autopsy identified multiple atelectases throughout both lower lobes."
Every year, millions of people develop atelectasis without ever knowing it — those tiny collapsed patches of lung after surgery are so common that radiologists see them daily.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of atelectasis
Atelectasis comes from the Greek 'atelēs' meaning 'incomplete' or 'imperfect' (from 'a-' meaning 'not' plus 'telos' meaning 'end, completion') combined with 'ektasis' meaning 'stretching' or 'extension'. It was adopted into medical Latin and entered English in the early nineteenth century. The same Greek root 'ektasis' appears in related medical terms such as 'bronchiectasis', while 'telos' underlies words like 'teleology'.
Related word forms
How atelectasis is actually used
Strictly a medical/clinical term used by physicians, radiologists, and respiratory therapists; it would sound overly technical in everyday conversation, where 'collapsed lung' is preferred. It carries a neutral, descriptive connotation rather than an alarming one — many forms are mild and asymptomatic. The adjective form 'atelectatic' is common in radiology reports.
Easily confused with atelectasis
Atelectasis is the collapse of lung tissue itself (airless alveoli), whereas pneumothorax is air trapped in the pleural space between the lung and chest wall, which can push on and compress the lung.
Atelectasis involves loss of air from the alveoli, while consolidation refers to lung tissue filled with fluid, pus, or other material instead of air, as in pneumonia.