Font Size
A
A
A

Residual Volume (RV)


Residual volume is the amount of air that remains in a person's lungs after fully exhaling. Doctors use tests to measure a person's residual air volume to help check how well the lungs are functioning.

Residual volume is measured by:

  • A gas dilution test. A person breathes from a container containing a documented amount of a gas (either 100% oxygen or a certain amount of helium in air). The test measures how the concentration of the gases in the container changes.
  • Body plethysmography. This test measures the total amount of air the lungs can hold (total lung volume). For this test, a person sits inside an airtight booth called a plethysmograph and breathes through a mouthpiece while pressure and air flow measurements are collected.
ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Specialist Medical ReviewerMark A. Rasmus, MD - Pulmonology, Critical Care Medicine, Sleep Medicine
Last RevisedApril 28, 2011

eMedicineHealth Medical Reference from Healthwise

This information does not replace the advice of a doctor. Healthwise 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.

To learn more visit Healthwise.org

© 1995-2012 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.





Medical Dictionary