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(Collapsed Lung)

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Definition | Causes | Risk Factors | Symptoms | Diagnosis | Treatment | Prevention


Atelectasis is a collapse of the air sacs in the lungs called alveoli. It may occur in a portion of the lung, or in the entire lung. Normally, oxygen enters the body through the lungs and is exchanged with carbon dioxide in the alveoli. The lungs expand and contract to create the exchange of these gases.

Atelectasis is not a disease, but a condition or sign that results from disease or abnormalities in the lungs.

The Lungs (Cut-away View)

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Atelectasis is caused by a:

  • Blockage of the airway
  • Reduced amount of surfactant, a liquid that keeps the lungs expanded

Blockage may be caused by:

  • Infection
  • Tumors, mucus, or a foreign object in the lungs
  • Compression, resulting from emphysema, an enlarged heart, or a tumor
  • Scarring that blocks the airway as a result of radiation therapy, frequent infections, or disease
  • Pneumothorax (leakage of air into the space surrounding the lungs)

Reduced amounts of surfactant may be caused by:

  • Lung immaturity in premature babies
  • Fluid accumulation
  • Failure to take deep breaths
  • Not coughing, which keeps the airway clear

Risk Factors

Factors that may increase your chance for atelectasis include:

  • Premature birth if lungs are not fully developed
  • Anesthesia
  • Restricted chest movement, due to bone or muscle problems, or recent abdominal surgery
  • Injuries
  • Prolonged bed rest with few changes in position
  • Mechanical ventilation
  • Lung diseases, such as asthma or lung cancer
  • Weakened respiratory muscles
  • Smoking
  • Heart failure
  • Obesity
  • Conditions that limit physical activity, such as a stroke, spinal cord injury, heart problems, trauma, or severe illness


Atelectasis may or may not cause symptoms. Small areas of collapse are less likely than larger areas to cause symptoms. Major atelectasis decreases the amount of oxygen available throughout the body.

Symptoms that may occur if a large area has collapsed include:

  • Rapid breathing
  • Shortness of breath
  • Taking shallow breaths
  • Coughing
  • Decreased chest movement during breathing
  • Mild fever
  • Rapid heart rate
  • Chest pain
  • Blueness of the lips or nails


The doctor will ask about your symptoms and medical history. A physical exam will be done. This may include listening to your lungs for changes in the normal sounds.

Tests may include:

Other tests may be needed to confirm or rule out the cause of the atelectasis.


Treatment focuses on treating the underlying cause and maintaining enough air supply. The collapsed lung usually expands after the underlying cause has been corrected. Mild atelectasis often goes away on its own without treatment.

Treatments include:

The therapist uses different techniques to help clear mucus from the lung. You will be positioned so that gravity helps secretions flow out of the body. When resting in bed, lie on the unaffected side to promote drainage from the lung area that has collapsed. Moving around will also help clear your lungs.

This may include any or all of the following:

  • Breathing masks or treatments to help keep your airways open
  • Incentive spirometry to help you learn to take deeper breaths
  • Suction to help remove secretions
  • A breathing machine, called a ventilator, if you are unable to breathe adequately on your own

Your doctor may recommend:

  • Medications to open the airways
  • Medications or therapy to treat the health condition that caused the collapse
  • Antibiotics to treat an infection
  • Oxygen, if you are having trouble breathing

Bronchoscopy may be used to remove a foreign body or mucus that is blocking the airway.


To help reduce your chance of atelectasis, take these steps.

  • If you need to, talk to your doctor about the best ways to quit smoking and lose weight.
  • If you have a chronic lung or heart condition, follow the treatment plan outlined by your doctor.
  • After surgery, follow instructions for deep breathing, coughing, and turning. Ask for pain medication if discomfort is limiting movement or coughing.

American Lung Association


National Heart Lung and Blood Institute



The Canadian Lung Association



Explore atelectasis. National Heart, Lung, and Blood Institute website. Available at: http://www.nhlbi.nih.gov/health/health-topics/topics/atl/. Updated January 13, 2012. Accessed September 19, 2013.

Behrman RE, et al. Nelson Textbook of Pediatrics. 18th ed. Philadelphia: Saunders; 2007.

Goldman L, Ausiello D, eds. Cecil Textbook of Internal Medicine. 23rd ed. Philadelphia: Saunders; 2008.

Mason, RJ et al. Murray & Nadel’s Textbook of Respiratory Medicine. 4th ed. Philadelphia: Saunders; 2007.

Spontaneous pneumothorax in adults. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed.ebscohost.com/about/about-us. Updated June 28, 2013. Accessed September 19, 2013.

Last reviewed September 2013 by Michael Woods, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.

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