Understanding the Urine Metanephrine (OS) 24-Hour Test
What It Is:
The Urine Metanephrine (OS) 24-Hour Test measures the amount of metanephrines in your urine over a 24-hour period. Metanephrines are byproducts of catecholamines, which are hormones produced by the adrenal glands.
This test helps diagnose conditions related to excess catecholamine production, such as pheochromocytomas and paragangliomas.
Why It's Done:
Diagnosing Pheochromocytomas and Paragangliomas:
Helps identify the presence of tumors that produce excess catecholamines, leading to symptoms such as high blood pressure, paleness, headaches, sweating, heart palpitations, and tremors2.
Assists in diagnosing conditions like pheochromocytomas (tumors in the adrenal glands) and paragangliomas (tumors outside the adrenal glands).
Monitoring Health:
Used to monitor the effectiveness of treatment for conditions affecting catecholamine production.
Helps evaluate symptoms such as episodic hypertension, palpitations, severe headaches, and sweating.
How the Test Works:
Procedure:
A healthcare professional will provide instructions on how to collect a urine sample over a 24-hour period. The sample should be collected in a clean, dry container and sent to a laboratory for analysis.
The test requires a complete 24-hour urine collection, starting from the first morning urine and including all urine passed during the day and night.
Understanding the Results:
Normal Range:
Normal levels of total urinary metanephrines are typically less than 400 micrograms (mcg) over 24 hours.
Abnormal Findings:
Elevated levels of metanephrines may indicate the presence of pheochromocytomas or paragangliomas2.
Further diagnostic tests, such as imaging studies (CT or MRI scans), may be recommended to confirm the diagnosis and locate the tumor.
Why Your Doctor Might Order This Test:
Symptoms of Catecholamine Excess:
If you have symptoms such as high blood pressure, paleness, headaches, sweating, heart palpitations, or tremors, this test can help diagnose the underlying cause.
Monitoring Treatment:
For patients undergoing treatment for pheochromocytomas or paragangliomas, this test helps monitor the effectiveness of therapy.
Symptoms That Might Prompt This Test:
High blood pressure
Paleness
Headaches
Sweating
Heart palpitations
Tremors
Lifestyle and Management:
Depending on your results, your healthcare provider might recommend further tests, treatments, or lifestyle changes to manage catecholamine-related conditions effectively.
Regular monitoring and follow-up are essential for successful treatment.