Vanillylmandelic acid (VMA)
A breakdown product of adrenaline and noradrenaline that is passed in the urine, usually measured in a 24-hour collection. Like metanephrines, it is used to look for a pheochromocytoma — a catecholamine-secreting tumour — and to help investigate neuroblastoma in children.
What it measures
Vanillylmandelic acid (VMA) is a final breakdown product of the catecholamine hormones adrenaline and noradrenaline, excreted in the urine. It is measured in a 24-hour urine collection, which averages out the ups and downs of hormone release over a full day. Historically VMA was the mainstay urine test for detecting a pheochromocytoma — the rare adrenal tumour that pours out catecholamines and causes spells of high blood pressure, headache, sweating and palpitations. Today the more sensitive metanephrine tests (in blood or urine) are usually preferred, but urinary VMA is still used, sometimes together with them, and remains a familiar part of the work-up. It has a second important role in children: VMA (with a related metabolite, HVA) is used in the assessment and monitoring of neuroblastoma, a childhood tumour of nerve-related tissue that also secretes catecholamines. Because a range of foods, drinks and medicines can affect the result, a VMA collection usually comes with dietary and drug restrictions in the days beforehand, and the level is interpreted against the total volume and timing of the collection.
What a high value can mean
- Pheochromocytoma or paraganglioma — a catecholamine-secreting tumour; the classic reason for a high VMA.
- Neuroblastoma — in children, a raised VMA (with HVA) supports the diagnosis and is followed during treatment.
- A mildly raised level — can be a false positive from certain foods (vanilla, coffee, bananas, chocolate), medications or stress if pre-test restrictions were not followed.
- Severe stress or acute illness — raises catecholamine output.
What a low value can mean
- Normal — the reassuring and expected result; argues against a catecholamine-secreting tumour.
When to discuss with a doctor
Urinary VMA is a specialist test used to look for a catecholamine-secreting tumour — a pheochromocytoma in adults, or neuroblastoma in children — when there are suggestive symptoms (spells of high blood pressure, headache, sweating, palpitations), resistant hypertension, an adrenal mass, or, in a child, signs of neuroblastoma. It is often paired with or replaced by the more sensitive metanephrine tests. Because vanilla-containing foods, coffee, certain fruits and some medicines can distort the result, the accuracy depends on following the pre-collection restrictions, and a mildly raised value is often repeated. A clearly high level prompts confirmation and imaging. Mediora.AI can surface a raised VMA alongside metanephrines and your blood pressure so the pattern is visible; confirming a tumour and any treatment belong with your specialist.