VMA (Vanillyl Mandelic Acid)-24hr Urine

A 24-hour urine VMA test measures vanillylmandelic acid, a breakdown product of catecholamines, in all urine collected over a full day. It helps detect catecholamine-secreting tumors (pheochromocytoma or neuroblastoma). Proper collection—collecting every void, refrigerating the container, and avoiding certain foods or medications beforehand—is essential for accurate results. Clinicians interpret results with symptoms and other tests.

Normal 24‑hour urinary vanillylmandelic acid (VMA) is generally reported as less than about 8–10 mg per 24 hours. Spot urine results may be given relative to creatinine and have different cutoffs. Reference ranges vary by laboratory, age and collection method, so test results should be interpreted by your healthcare provider in context.

Normal 24‑hour urine results: volume 800–2,000 mL; creatinine excretion ~14–26 mg/kg/day (men) and 11–20 mg/kg/day (women); total protein <150 mg/24 h; albumin <30 mg/24 h; calcium about 100–300 mg/24 h; sodium roughly 40–220 mmol/24 h; potassium roughly 25–125 mmol/24 h. Consult your clinician for interpretation.

A positive VMA (vanillylmandelic acid) test means urinary breakdown products of catecholamines are elevated. This suggests increased catecholamine production, commonly seen with pheochromocytoma, neuroblastoma or paraganglioma, but can also result from stress, certain foods or medications. It’s not diagnostic alone—further biochemical tests, imaging and specialist evaluation are needed to confirm the cause and guide treatment.

Elevated vanillylmandelic acid (VMA) indicates increased catecholamine breakdown, often due to catecholamine-secreting tumors (pheochromocytoma or neuroblastoma). It may be associated with hypertension, headaches, sweating and palpitations. A high VMA prompts repeat testing with dietary/medication precautions, measurement of plasma metanephrines/catecholamines, and imaging to locate a tumor for definitive diagnosis and management.

A 24‑hour urine collection measures substances excreted over a full day to assess kidney function and quantify abnormal losses. It’s used to calculate creatinine clearance, measure protein (proteinuria), electrolytes and minerals (calcium, sodium), hormones and metabolites (cortisol, catecholamines, metanephrines), and detect metabolic disorders or stone risk. Results guide diagnosis and treatment monitoring.