Whole Body Water Content by Bioelectrical Impedance Spectroscopy (BIS)
This test measures the proportion of water in your total body weight using a gentle electrical signal. It helps assess hydration status and body composition.
["This test estimates how much of your body weight comes from water, useful for hydration and weight management evaluations."]
Key facts at a glance
- LOINC
- 44139-4
- Short code
- PT Whole body W RNC IV
- Synonyms
- PT Whole body W RNC IV
- Category
- chemistry
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- pt
- CPT
- 85610
- SNOMED
- 396252006
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
How the Test Works
During this test, you’ll stand on a special platform while electrodes detect the body’s electrical resistance. The device calculates water content based on how electricity travels through your body tissues.
What to Expect
The process is quick and painless—you’ll stand still for about 30 seconds. No preparation is needed, but avoid drinking large amounts of water before testing for accuracy.
Why It’s Done
Doctors may order this test to evaluate hydration levels, monitor weight changes, or assess conditions like muscle loss, edema, or metabolic disorders.
Possible Results Interpretation
Results are expressed as a percentage of total body weight. Lower percentages may indicate dehydration or fat loss, while higher percentages could suggest fluid retention or muscle gain.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical significance: This test provides a non-invasive way to assess hydration and body composition, which can be critical in managing chronic conditions like heart failure, kidney disease, or obesity. It may also help track progress in weight management programs.
Short name
Whole Body Water %
Frequently asked questions
What does a low whole body water percentage mean?
How does diet or exercise affect this test?
Is this test covered by insurance?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy