Free Metanephrine (Serum)
This test measures the naturally occurring chemical called free metanephrine in your blood. It helps assess whether you have a condition called pheochromocytoma or paraganglioma, which causes the adrenal glands or other parts of your body to produce too much hormone.
["Free metanephrine levels can indicate rare but serious hormone-related disorders."]
Key facts at a glance
- LOINC
- 87499-0
- Short code
- Free 3-MT Ur-sRto
- Synonyms
- Free 3-MT Ur-sRto
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Is Done
Your doctor may order this test if you have symptoms like severe headaches, high blood pressure, sweating, rapid heartbeat, or unexplained weight loss. It’s also used to check for conditions like pheochromocytoma or paraganglioma, which can cause excessive hormone production.
How the Test Works
A small blood sample is taken from a vein in your arm. The blood is then analyzed in a lab to measure free metanephrine levels. This test helps doctors determine if abnormal hormone levels are present that could cause health problems.
What to Expect Before the Test
No special preparation is needed, but you may be asked to stop certain medications that could affect results. If you have high blood pressure, your doctor might advise you to monitor it before the test.
What the Results Mean
High levels of free metanephrine may suggest a tumor in your adrenal glands or other parts of your body that produces too much hormone. Low levels are less commonly associated with this condition but can be part of a broader evaluation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated free metanephrine levels strongly support a diagnosis of pheochromocytoma or paraganglioma. These tumors can cause dangerous symptoms like severe hypertension, palpitations, and anxiety. Early detection is important to guide treatment and prevent complications.
Short name
Free Metanephrine
Frequently asked questions
What causes abnormal free metanephrine levels?
How long does it take to get results?
Can I eat or drink before this test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy