A plasma free metanephrines test measures circulating metanephrine and normetanephrine to screen for or diagnose catecholamine-secreting tumors (pheochromocytoma or paraganglioma). It's used when patients have unexplained high blood pressure, headaches, sweating, or palpitations. The test is highly sensitive; proper preparation (resting supine, avoiding certain medications) reduces false positives and guides further imaging and specialist referral.

Normal plasma free metanephrine concentrations are typically below about 0.5 nmol/L (metanephrine) and below about 0.9 nmol/L (normetanephrine). Reference ranges can vary by laboratory, assay method and patient posture; higher results may prompt further testing for catecholamine‑secreting tumors. Interpret values with clinical context and follow-up testing ordered by a clinician.

Costs vary widely: under public health systems it’s often covered, while private lab prices commonly range from about $50–$400 USD (plasma or 24‑hour urine); in India typical private‑lab fees are roughly ₹800–₹3,000. Specialized hospital testing or add‑ons can raise fees to several hundred dollars. Final cost depends on test type (plasma free vs 24‑hour urine), location, and insurance coverage.

High metanephrine means elevated breakdown products of catecholamines, often indicating an overproducing tumor such as a pheochromocytoma or paraganglioma. It can cause hypertension, headaches, sweating, palpitations and anxiety. False elevations may result from certain medications, stress, or improper sample handling. Follow-up usually involves repeat or plasma testing, medication review, imaging (CT/MRI) and referral to an endocrinologist for diagnosis and management.

Metanephrines (metanephrine and normetanephrine) are biochemical tumor markers used to detect pheochromocytoma and paraganglioma. Elevated plasma or urinary metanephrines strongly suggest these catecholamine-secreting tumors and guide diagnosis and monitoring, but elevations can occur with certain medications, stress, or other conditions, so abnormal results require clinical correlation and confirmatory testing. Testing is highly sensitive when performed properly.

Adrenal gland tumors can be functional or nonfunctional. Functional tumors cause hormone-specific symptoms: excess cortisol—weight gain (central obesity), round face, purple stretch marks, muscle weakness, high blood pressure, glucose intolerance; excess aldosterone—persistent high blood pressure, low potassium with muscle cramps and weakness; excess catecholamines (pheochromocytoma)—episodic headaches, rapid heartbeat, sweating, anxiety and blood pressure spikes. Nonfunctional tumors may cause abdominal/back pain or be asymptomatic.