Alternative names
Partial lung collapse

Atelectasis is the collapse of part or all of a lung by blockage of the air passages (bronchus or bronchioles), or by very shallow breathing. See also Pneumothorax.

Causes, incidence, and risk factors

Anesthesia, prolonged bed rest with few changes in position and shallow breathing, and underlying lung diseases are risk factors for atelectasis. Secretions that plug the airway, foreign objects (common in children) in the airway, and tumors that obstruct the airway may lead to atelectasis.

In an adult, small regions of atelectasis are usually not life-threatening, because unaffected parts of the lung compensate for the loss of function in the affected area. Large-scale atelectasis, especially in someone who has another lung disease or illness may be life-threatening. In a baby or small child, lung collapse due to a mucus obstruction or other causes can be life-threatening.

Massive atelectasis may result in the collapse of a lung.


  • Breathing difficulty  
  • Chest pain  
  • Cough

Signs and tests


The goal of treatment is to remove pulmonary (lung) secretions and re-expand the affected lung tissue.

The following treatments may be implemented:

  • Positioning on the unaffected side to allow re-expansion of lung  
  • Removal of the obstruction, if present, by bronchoscopy or another procedure  
  • Deep breathing exercises (incentive spirometry)  
  • Percussion of the chest to loosen secretions (clapping)  
  • Positioning so that secretions drain by gravity where they can be coughed up (postural drainage)  
  • Treatment of tumor or underlying condition, if present

Expectations (prognosis)
The collapsed lung usually re-inflates gradually once the obstruction has been removed, although some residual scarring or damage may be present.

Pneumonia may develop rapidly after atelectasis.

Calling your health care provider
Call your health care provider if you develop symptoms of atelectasis.


  • Keep small objects out of the reach of young children.  
  • Maintain deep breathing after anesthesia.  
  • Encourage movement and deep breathing in anyone who is bedridden for long periods.

Johns Hopkins patient information

Last revised: December 2, 2012
by Arthur A. Poghosian, M.D.

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