Urea/Creatinine Ratio, 24-Hour Urine
Measures the relative amounts of urea and creatinine in urine collected over 24 hours to help assess kidney function and hydration status.
["This test compares urea with creatinine in a 24-hour urine collection and can provide information about kidney function and hydration."]
Key facts at a glance
- LOINC
- 25999-4
- Short code
- Urea/Creat 24h Ur-sRto
- Synonyms
- Urea/Creat 24h Ur-sRto
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 7
- Ref high
- 20
- Critical range
- — – 100 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84520
- SNOMED
- 2739004
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
What is this test?
This test measures urea and creatinine in urine collected for 24 hours and calculates their ratio. Creatinine is a waste product filtered by the kidneys, while urea is formed in the liver when protein is broken down.
Why might I need this test?
Your clinician may order this test as part of an evaluation of kidney function, hydration, or how the body is handling protein. It may also help interpret the amounts of urea and creatinine measured in a 24-hour urine collection.
How is the test performed?
You collect all urine produced during a full 24-hour period, following the collection instructions provided by the laboratory. The urine is then analyzed, and the amount of urea is compared with the amount of creatinine.
How do I prepare for the test?
Begin and end the collection at the specified times and record both times. Keep the container closed and refrigerate it if instructed by the laboratory. Do not change your diet, fluid intake, or medications unless your clinician specifically tells you to do so.
Reference range
Adult: 7-20 mg/dLN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A higher-than-expected urea-to-creatinine ratio may occur with dehydration, high protein intake, or increased urea production, while a lower ratio may occur with low protein intake, reduced urea production, or other changes in kidney function. Abnormal results should be interpreted by your clinician because diet, hydration, medications, and collection completeness can affect them.
Short name
24-Hour Urine Urea/Creatinine Ratio
Frequently asked questions
Why is a 24-hour urine collection needed?
What happens if the collection is incomplete?
Does the result diagnose kidney disease by itself?
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