Residual Volume Definition by Healthwise:
Residual volume is the amount of air that remains in a person's lungs after fully exhaling. Health professionals use tests to measure a person's residual air volume to help evaluate 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.
| Author: | Jeannette Curtis |
| Medical Review: | Patrice Burgess, MD - Family Medicine Adam Husney, MD - Family Medicine Kathleen Romito, MD - Family Medicine |
| Last Updated: May 25, 2007 | |
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