Main content

    Health Information

    Forced Expiratory Volume and Forced Vital Capacity

    Forced Expiratory Volume and Forced Vital Capacity

    Topic Overview

    Forced expiratory volume (FEV) measures how much air a person can exhale during a forced breath. The amount of air exhaled may be measured during the first (FEV1), second (FEV2), and/or third seconds (FEV3) of the forced breath.

    Forced vital capacity (FVC) is the total amount of air exhaled during the FEV test.

    Forced expiratory volume and forced vital capacity are lung function tests that are measured during spirometry . Forced expiratory volume is the most important measurement of lung function. It is used to:

    • Diagnose obstructive lung diseases such as asthma and chronic obstructive pulmonary disease (COPD) . A person who has asthma or COPD has a lower FEV1 result than a healthy person.
    • See how well medicines used to improve breathing are working.
    • Check if lung disease is getting worse. Decreases in the FEV1 value may mean the lung disease is getting worse.

    Related Information

    Credits

    By Healthwise Staff
    E. Gregory Thompson, MD - Internal Medicine
    Robert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology
    Last Revised November 28, 2012

    This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

    1995-2014 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.