Main AHCA Website

AHCA’s main website for information on Medicaid, Health Quality Assurance and the Florida Center for Health Information and Transparency.

Go >

Florida Health Information Network

This website provides information and resources relating to AHCA’s initiatives for Health Information Technology and Health Information Exchange.

Go >

Provides health education and information to compare and locate health care providers in Florida to make well-informed health care decisions.

Go >
AHCA Network of Websites

Health Education

Health Encyclopedia

Search the Health Encyclopedia



Atelectasis is the collapse of part or (much less commonly) all of a lung.

Alternative Names

Partial lung collapse


Atelectasis is caused by a blockage of the air passages (bronchus or bronchioles) or by pressure on the outside of the lung.

Another type of collapsed lung is called pneumothorax. It occurs when air escapes from the lung. The air then fills the space outside of the lung, between the lung and chest wall.

Atelectasis is common after surgery or in patients who were in the hospital.

Risk factors for developing atelectasis include:

  • Anesthesia
  • Foreign object in the airway (most common in children)
  • Lung diseases
  • Mucus that plugs the airway
  • Pressure on the lung caused by a buildup of fluid between the ribs and the lungs (called a pleural effusion)
  • Prolonged bed rest with few changes in position
  • Shallow breathing (may be caused by painful breathing)
  • Tumors that block an airway


Exams and Tests

To confirm if you have atelectasis, the following tests will likely be done:


The goal of treatment is to re-expand the collapsed lung tissue. If fluid is putting pressure on the lung, removing the fluid may allow the lung to expand.

Treatments for atelectasis include one or more of the following:

  • Clap (percussion) on the chest to loosen mucus plugs in the airway
  • Perform deep breathing exercises (with the help of incentive spirometry devices)
  • Remove or relieve any blockage in the airways by bronchoscopy.
  • Tilt the person so the head is lower than the chest (called postural drainage). This allows mucus to drain more easily.
  • Treat a tumor or other condition, if there is one
  • Turn the person to lie on the healthy side, allowing the collapsed area of lung to re-expand
  • Use aerosolized respiratory treatments (inhaled medications) to open the airway
  • Use other devices that help increase positive pressure in the airways and clear fluids (positive expiratory pressure [PEP] devices)

Outlook (Prognosis)

In an adult, atelectasis in a small area of the lung is usually not life threatening. The rest of the lung can make up for the collapsed area, bringing in enough oxygen for the body to function.

Large areas of atelectasis may be life threatening, especially in a baby or small child, or in someone who has another lung disease or illness.

The collapsed lung usually reinflates slowly if the airway blockage has been removed. Scarring or damage may remain.

The outlook depends on the underlying disease. For example, people with extensive cancer have a poor prognosis, while patients with simple atelectasis after surgery have a good prognosis.

Possible Complications

Pneumonia may develop quickly after atelectasis in the affected part of the lung.

When to Contact a Medical Professional

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


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


O'Donnell AE. Bronchiectasis, atelectasis, cysts, and localized lung disorders. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 90.

Review Date:8/25/2014
Reviewed By:Denis Hadjiliadis, MD, Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997-A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.

Outcome Data

No data available for this condition/procedure.

Health Encyclopedia

More Features

We Appreciate Your Feedback
1. Did you find this information useful?

2. Would you recommend this website to family and friends?