Vanillylmandelic Acid (VMA), 24-hr Urine
7,250 Kshs | Home Collection Available
Synonyms
3-Methoxy-4-hydroxymandelic acid, VMA
Purpose
The Vanillylmandelic Acid (VMA) Test measures the amount of VMA, a major breakdown product (metabolite) of catecholamines, specifically epinephrine (adrenaline) and norepinephrine (noradrenaline) in a 24-hour urine sample.
Healthcare providers use this test primarily to help:
- Diagnose and monitor catecholamine-secreting tumors such as neuroblastoma, pheochromocytoma, and paraganglioma
- Investigate symptoms like persistent or episodic high blood pressure, headaches, sweating, rapid heartbeat, or unexplained weight loss
- Evaluate children with suspected neuroblastoma, particularly when presenting with abdominal masses, irritability, or bone pain
- Because VMA levels reflect the long-term metabolism of catecholamines, the test provides a more stable marker for tumor activity compared to direct catecholamine measurements.
The VMA test aids early detection of certain rare but serious tumors, helping to monitor treatment success or detect recurrence after tumor removal.
To improve diagnostic accuracy and provide a comprehensive evaluation, the test can be done alongside a Urine Catecholamines Test, a 24-Hour Urine or Plasma Metanephrines, Plasma Free Metanephrines Test, Imaging Studies, a Homovanillic Acid (HVA) Test, and Chromogranin A Blood Test.
The VMA test is a valuable tool in the diagnosis and management of adrenal and sympathetic nervous system tumors, particularly in children.
Patient Preparation
The patient should avoid caffeine, phenothiazine, and antihypertension agents for 72 hours before testing.
Samples
4ml aliquot with a minimum volume of 1ml of urine 24-hour collected in a plastic urine container without preservatives. All urine should be collected, including the final specimen at the end of the 24-hour collection period, mixed, and the lid secured. Label the container with the patient’s details (name, date of collection time). Store the sample at room temperature for 7 days.
Reference Range
0.0-7.5 mg/24hrs
Results Turnaround
3-4days after receipt of samples.
Diseases / Diagnostic indicators
The VMA test helps detect and monitor tumors that secrete excess catecholamines or arise from nerve tissue. Elevated levels of vanillylmandelic acid in urine are commonly associated with:
- Pheochromocytoma – a tumor of the adrenal glands that causes episodes of severe hypertension, palpitations, sweating, and anxiety
- Ganglioneuroblastoma / Neuroblastoma – tumors derived from nerve tissues, typically affecting infants and young children, and often presenting with an abdominal mass, bone pain, or unexplained weight loss.
- Paraganglioma – a tumor similar to pheochromocytoma but located outside the adrenal glands
These tumors may cause the body to produce excessive catecholamines, which are broken down into VMA and excreted in the urine.
The test results may indicate:
Elevated VMA Levels:
This suggests the presence of a catecholamine-secreting tumor such as pheochromocytoma, neuroblastoma, or paraganglioma. Further diagnostic imaging and confirmatory tests are usually recommended.
Normal VMA Levels:
These rules out significant catecholamine overproduction. However, in some cases, especially if the tumor secretes hormones intermittently or at low levels, repeat testing or alternative markers (like metanephrines) may still be needed.
Mildly Elevated Levels:
May occur due to stress, certain foods, or medications (e.g., antidepressants, decongestants). A thorough review of history and possibly a retest under controlled conditions may be necessary.
The VMA test plays a key role in identifying and managing rare endocrine tumors and helps guide further diagnostic and treatment steps.
For more on Vanillylmandelic Acid (VMA), 24-hr Urine test, read this study.