VMA Full Profile: Definition, Types, Measurement, and Clinical Relevance

Vanillylmandelic acid (VMA) is a stable end metabolite of catecholamines—epinephrine and norepinephrine—and serves as a key biomarker in the evaluation of suspected catecholamine-secreting tumors, most notably pheochromocytoma and paraganglioma. Measurement of VMA in urine or plasma helps clinicians assess excess catecholamine production when imaging and acute testing are inconclusive. This evergreen explainer defines VMA, describes collection and assay methods, reviews reference ranges and factors that can affect results, and outlines how VMA fits into the broader diagnostic pathway for catecholamine excess disorders.