Vanillylmandelic Acid to Creatinine Ratio, 24-Hour Urine
A 24-hour urine test that measures vanillylmandelic acid relative to creatinine to help evaluate catecholamine-producing tumors.
["This test looks for evidence of increased catecholamine production, which can occur with certain rare tumors."]
Key facts at a glance
- LOINC
- 50948-9
- Short code
- VMA & Creat 24h Ur-Imp
- Synonyms
- VMA & Creat 24h Ur-Imp
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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?
Vanillylmandelic acid, or VMA, is a substance formed when the body breaks down catecholamines, including epinephrine and norepinephrine. This test measures VMA relative to creatinine in urine collected over 24 hours.
Why might I need this test?
The test may be used to help evaluate suspected catecholamine-producing tumors, especially neuroblastoma in children or pheochromocytoma and related tumors in adults. It may also be used to follow certain people who have already been diagnosed with these conditions.
How is the test performed?
You collect all urine for a full 24-hour period, and the laboratory measures the VMA and creatinine amounts. Comparing VMA with creatinine helps account for differences in how concentrated the urine sample is.
How do I prepare for the test?
Follow the collection instructions provided by the laboratory, including the exact start and stop times. Refrigerate the urine or use a preservative only if instructed, and tell the care team about any missed samples. Ask about food, caffeine, exercise, or medication restrictions, and do not stop medicines without medical advice.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated VMA-to-creatinine ratio can indicate increased catecholamine production, as may occur with neuroblastoma, pheochromocytoma, or another rare tumor. Results must be interpreted with symptoms, age, medications, and other tests because mild increases can have other causes. This result alone does not establish a tumor diagnosis.
Short name
24-Hour Urine VMA/Creatinine Ratio
Frequently asked questions
What does VMA measure?
Why is VMA compared with creatinine?
How is the 24-hour urine sample collected?
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