Table of Contents
FDA Consumer magazine
March-April 1999
The lungs are uniquely designed to provide an uninterrupted flow of oxygen to the blood when a person inhales, and to eliminate carbon dioxide (waste gas) upon exhaling--quickly, efficiently, in the right amounts, and all without our being aware of it. The lungs' ability to stretch and then return to their original shape after expiration is crucial to the process of breathing because without doing so, there would be no air movement. When the lungs cannot exhale enough carbon dioxide, a toxic buildup occurs, poisoning all the cells of the body. Any factor that causes the airways to constrict or narrow, or which causes the lungs to become less resilient, will increase the work of breathing.