What is COPD?

    Written by:
    Marina Shkayeva

    Fact-checked

    by:

    Morgan Pfiffner, Shyam Jayaraman
    Last Updated: May 16, 2025

    Chronic obstructive pulmonary disease (COPD) is a chronic condition characterized by irreversible lung damage, which leads to symptoms like difficulty breathing and cough. It typically involves both emphysema, in which air sacs in the lungd lose elasticity, and chronic bronchitis, which is marked by airway inflammation and increased mucus production.

    COPD is a chronic condition which occurs due to irreversible damage to the lungs with common symptoms such as trouble breathing and cough.[1]

    Normal lungs have many small stretchy air sacs that inflate upon inhalation and deflate upon exhalation. With COPD, less air can enter the lungs because air sacs have damaged walls and are less stretchy (this is called emphysema); and the airway becomes inflamed triggering cough and more mucus production (this is called chronic bronchitis). Most people have a COPD with both emphysema and chronic bronchitis, with variable severity.[2]