24-Hour Urinary VMA

Function

Vanillylmandelic Acid (VMA) is one of the primary breakdown products (metabolites) of catecholamines, specifically epinephrine (adrenaline) and norepinephrine. These hormones are produced by the adrenal glands and are central to the body's 'fight or flight' response. The 24-hour urine test measures the total amount of VMA excreted over a full day, providing a window into catecholamine production.

Why it is Ordered

Physicians order a VMA test primarily to screen for rare tumors that secrete catecholamines. It is a critical diagnostic tool when a patient presents with episodic high blood pressure, severe headaches, or palpitations. It is also used to monitor the effectiveness of treatment in patients known to have these neuroendocrine tumors.

Associated Conditions

• Pheochromocytoma: A usually benign tumor of the adrenal gland that causes excessive adrenaline release.
• Neuroblastoma: One of the most common solid tumors in children, arising from immature nerve cells.
• Ganglioneuroma: A rare, benign tumor of the autonomic nervous system.
• Severe Stress: Significant physical or emotional stress can transiently elevate catecholamine metabolites.