Forced Expiratory Volume and Forced Vital Capacity

Coronavirus

See the latest Coronavirus Information including testing sites, visitation information, appointments and scheduling, location hours, data and more.

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

Current as of: February 24, 2020

Author: Healthwise Staff

Medical Review:

E. Gregory Thompson MD - Internal Medicine

Adam Husney MD - Family Medicine

Elizabeth T. Russo MD - Internal Medicine