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  • Cynthia M. Johnson, MA
Publication Type:



(Collapsed Lung)


Atelectasis is a collapse of the air sacs in the lungs. It may occur in part or all of the lung. It can make it hard to breathe.

The Lungs (Cut-away View).

Nucleus factsheet imagehttp://services.epnet.com/getimage.aspx?imageiid=49204920BQ00030.jpgBQ00030.jpgNULLjpgNose airway to lungsNULL\\filer01a\Intellect\images\BQ00030.jpgNULL11NULL2003-04-163803904920_12032Copyright © Nucleus Medical Media, Inc.


Atelectasis is caused by:

  • A blocked airway, such as from a foreign body, mucus plug, or tumor
  • Pressure outside the airway, such as from:
    • Injury
    • Scarring
    • Fluid buildup
    • Infection
  • Suppressed breathing or coughing
  • Reduced surfactant—a fluid that keeps the lungs expanded

Risk Factors

Things that may raise the risk of atelectasis are:


Some people may not have symptoms. A large area of collapse is more likely to cause symptoms. Problems may be:

  • Breathing that is fast, difficult, or shallow
  • Coughing
  • Mild fever
  • Fast heart rate
  • Chest pain
  • Blueness of the lips or nails


The doctor will ask about symptoms and health history. A physical exam will be done. This will include listening to lung sounds.

The airways will need to be viewed. This can be done with:

Other tests may be needed to find a cause.


Mild atelectasis often goes away on its own without treatment. In others, the goal is to treat the underlying cause and maintain enough oxygen. The collapsed lung usually expands when the cause has been corrected.


Therapy will be needed to help with breathing, such as:

  • Physical therapy—to help clear mucus from the lung
  • Oxygen—to assist with breathing
  • Respiratory therapy, such as:
    • Breathing masks or treatments—to keep the airway open
    • Incentive spirometry—to promote deep breathing
    • Suction—to help remove fluid and mucus build up
    • Mechanical ventilation—in people who cannot breathe on their own


Medicine may be given to:

  • Open airways
  • Treat the condition that caused atelectasis
  • Fight infections


A bronchoscopy may be done to remove a foreign body from the lung.


To lower the risk of atelectasis:





  • Atelectasis. Merck Manual Professional Version website. Available at: http://www.merckmanuals.com/professional/pulmonary-disorders/bronchiectasis-and-atelectasis/atelectasis.
  • Chest x-ray patterns in the differential diagnosis of lung disorders. EBSCO DynaMed website. Available at: https://www.dynamed.com/evaluation/chest-x-ray-patterns-in-the-differential-diagnosis-of-lung-disorders.
  • Respiratory distress syndrome (RDS). National Heart, Lung, and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health/respiratory-distress-syndrome.
  • Marini JJ. Acute lobar atelectasis. Chest. 2019;155(5):1049-1058.


  • David L. Horn, MD, FACP
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.