Bronchiolitis Obliterans with Organizing Pneumonia (BOOP) | American Lung Association

Location Select your location

Bronchiolitis Obliterans with Organizing Pneumonia (BOOP)

Bronchiolitis obliterans with organizing pneumonia (BOOP), also called Cryptogenic Organizing Pneumonia (COP), is a rare lung condition affecting the small airways (bronchioles), alveoli (tiny air sacs) and the walls of small bronchi. This pattern of lung damage involving inflammation and stiffening of affected lung areas with connective tissue can result from a variety of causes. Sometimes, a cause cannot be determined for this form of lung injury.

Key Facts

  • BOOP/COP is a rare type of lung damage that has many potential causes but often a specific cause cannot be identified.
  • In most cases, gradual onset of shortness of breath and dry cough are symptoms of BOOP/COP.
  • Oral steroids, such as prednisone, are the most common treatment for BOOP/COP.
  • The disease may recur in some cases, especially if steroids are withdrawn too quickly.

View our Cryptogenic Organizing Pneumonia (COP) section to learn more »


This content was developed in partnership with the CHEST Foundation, the philanthropic arm of the American College of Chest Physicians.

Ask An Expert

Questions about your lung health? Need help finding healthcare? Call 1-800-LUNGUSA.

Get help
We need your generous support

Make a difference by delivering research, education and advocacy to those impacted by lung disease.

What is LUNG FORCE?

LUNG FORCE unites women and their loved ones across the country to stand together in the fight against lung cancer.

Get involved
Join the fight for healthy lungs and healthy air.
Donate Now.