Normetanephrine 24 hour Urine

This test measures the amount of normetanephrine in your urine collected over a full day. Normetanephrine is a breakdown product of norepinephrine, a chemical messenger involved in the body’s stress response. It is formed inside cells after norepinephrine is released and metabolized, then cleared by the kidneys into urine.

Collecting urine for a full day helps capture fluctuations that can occur from hour to hour. The result reflects your overall production of this metabolite across daily activities and sleep, which can be more informative than a single spot sample.

Doctors use this test to evaluate symptoms that can be caused by tumors that make excess catecholamines, such as pheochromocytoma or paraganglioma. It may be ordered if you have spells of pounding heartbeat, headaches, sweating, paleness, or hard to control blood pressure, or if an adrenal or extra‑adrenal mass was found on imaging. It can also be used to monitor after treatment for these conditions.

Because normetanephrine comes from norepinephrine metabolism, levels can also reflect your body’s stress physiology, medications, and other health conditions. Understanding whether an elevation is due to a true disease or to another factor helps guide safe and timely next steps.

Your result is interpreted with your symptoms, exam findings, and other tests. A higher value can support the possibility of a catecholamine‑producing tumor, but it is not a diagnosis by itself. Smaller increases can occur with stress, certain medicines, intense exercise, or issues with the collection. Low results are usually not concerning.

If results raise concern, your clinician may recommend repeat testing under controlled conditions, plasma metanephrines, or additional studies. Accurate collection over a full day is important, and your team may review medicines and diet that could interfere. If results remain concerning, imaging or specialist referral may be suggested. Always discuss what your specific result means for you.