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Urinalysis
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Currently under review
Pending specialist review and validation.
This test measures the amount of norepinephrine (also called noradrenaline) your body excretes into the urine over a full 24-hour collection. Norepinephrine is a hormone and neurotransmitter produced mainly by the adrenal glands and certain nerve cells that helps regulate blood pressure, heart rate, and the body’s stress response.
Because norepinephrine levels can rise and fall during the day, collecting all urine for a full day provides a more complete picture than a single spot sample. The test is often ordered alongside other catecholamine or metanephrine tests to evaluate how your body is producing and clearing these stress-related chemicals.
Doctors use this test to look for causes of symptoms such as sudden headaches, palpitations, sweating, anxiety, and sustained or difficult-to-control high blood pressure. One important reason to measure urinary norepinephrine is to help detect rare tumors that make excess catecholamines, such as pheochromocytomas or paragangliomas. The test can also help monitor treatment or follow-up after such conditions are managed.
Results can be influenced by stress, illness, and certain medicines, so your healthcare team may give you preparation instructions. Understanding your norepinephrine output can guide further testing, imaging, or changes in medications to address symptoms and reduce cardiovascular risks.
Your result is interpreted alongside your symptoms, blood pressure readings, other lab tests such as metanephrines, and any medicines you take. A higher-than-expected value can occur with catecholamine-secreting tumors, but it can also be seen with stress, intense exercise, pain, or certain drugs. A lower-than-expected value is usually not concerning on its own.
If your result is higher than expected, your clinician may repeat testing, review your medications and collection technique, or order complementary tests. If a tumor is suspected, imaging studies may be considered. If your result is within the expected range yet symptoms persist, your care team may explore other causes of your blood pressure or symptom pattern.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
Decongestants, antidepressants (such as tricyclics or MAO inhibitors), stimulants, beta blockers, clonidine, and some herbal products can raise or lower norepinephrine results. Always review your medication list with your clinician before collection.
Caffeine, nicotine, alcohol, and certain foods or energy drinks can affect catecholamine release and metabolism. You may be asked to limit these items before and during the collection to avoid misleading results.
Acute stress, panic, pain, fever, and vigorous exercise can temporarily increase norepinephrine. Try to maintain usual activity and avoid strenuous workouts during the collection period if your clinician advises.
Incomplete timing, missed voids, or spilling part of the urine can invalidate results. Start after emptying your bladder, collect all urine for the full 24 hours, and keep the container cool as instructed.
Reduced kidney function can change how catecholamines are cleared, which may alter measured amounts. Your clinician may consider kidney tests when interpreting your result.
Physiologic changes in pregnancy and in children can influence catecholamine patterns. Tell your clinician if you are pregnant or collecting for a child so the result can be interpreted appropriately.
References