Vanillylmandelic Acid-to-Creatinine Ratio, 24-Hour Urine
Measures the amount of vanillylmandelic acid (VMA), a catecholamine breakdown product, relative to urine creatinine collected over 24 hours.
["This urine test can help evaluate suspected neuroblastoma or pheochromocytoma by measuring a catecholamine metabolite."]
Key facts at a glance
- LOINC
- 30571-4
- Short code
- VMA/Creat 24h Ur
- Synonyms
- VMA/Creat 24h Ur
- 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 breakdown product of catecholamines such as epinephrine and norepinephrine. This test measures VMA relative to creatinine in urine collected for 24 hours. The creatinine comparison helps account for differences in urine concentration.
Why might I need this test?
This test may be used to help evaluate tumors that produce catecholamines, particularly neuroblastoma in children and pheochromocytoma in adults. It is usually ordered as part of an evaluation for symptoms or findings that suggest excess catecholamine production.
How is the test performed?
You collect all urine for a full 24-hour period in the container provided by the laboratory. The laboratory then measures VMA and creatinine and calculates their ratio. Follow the laboratory's instructions about the collection start time, container, storage, and preservative.
How do I prepare for the test?
Plan to collect urine for exactly 24 hours and record when the collection begins and ends. Ask your clinician whether any medications, foods, or drinks should be avoided. If you miss part of the collection or vomit into the container, contact the laboratory for instructions.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
An elevated VMA-to-creatinine ratio may indicate increased catecholamine production, as can occur with neuroblastoma or pheochromocytoma. Results can also be affected by collection errors or certain foods, medications, and medical conditions, so abnormal results should be interpreted by a clinician and may require repeat or confirmatory testing.
Short name
24-Hour Urine VMA-to-Creatinine Ratio
Frequently asked questions
Why is creatinine included in the result?
How long must urine be collected?
Does an abnormal result confirm a tumor?
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