Health Encyclopedia
Search Clinical Content Search Patient Health Library
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A-Z Listings

Your Child's Asthma: What Happens in the Lungs 

When lungs are healthy, breathing is easy. With each breath, air goes down the windpipe (trachea) into the lungs. There, it flows through airways called bronchial tubes. The airways also make mucus to trap and help get rid of any particles that are breathed in. Muscles that wrap around the airways help with breathing. Air is breathed out through the same airways.

Child's head and torso showing upper and lower respiratory tracts.

How asthma affects the lungs

Here's how asthma affects the lungs: 

  • With asthma, the airways are inflamed. The lining of the airways swells. Muscles around the airways may be tight. Air has to go through a narrower tube.

  • With asthma, the lungs are too sensitive to things that are breathed in. This causes inflammation. It also causes the lungs to make more mucus.

  • With asthma flare-ups, the airways can become even more swollen. The muscles around the airways tighten. More mucus forms. All of this narrows the airways even more. This causes breathing trouble—an asthma flare-up.

Normal bronchiole, a tightened bronchiole with asthma, and constricted bronchiole with excess mucus during asthma flareup.

Online Medical Reviewer: Chelsey Schilling BSN RN
Online Medical Reviewer: Jessica Gotwals RN BSN MPH
Date Last Reviewed: 4/1/2025
© 2000-2025 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.
Powered by Krames by WebMD Ignite

These resources and their content are provided by a third party for informational purposes and do not necessarily reflect the values and positions of Ascension, its ministries, or its subsidiaries.

About StayWell | Terms of Use | Privacy Policy | Disclaimer

The Services may integrate with Third-Party Apps or contain third-party content or provide links to third-party websites. For example, the Services may integrate with Third-Party App providers to provide you with information. You authorize Ascension to transmit information about You to and receive information about You from applicable third parties.
You agree that Ascension is not responsible for Third-Party Apps, third-party content or third-party websites, and does not make any endorsements, representations or warranties regarding the same. Your use thereof is at Your own risk and subject to the third party’s terms and conditions, as applicable. By using a Third-Party App or third-party content or websites, You agree to the applicable third party’s terms and conditions, even if Ascension does not present them to You at the time of Your use.