Norepinephrine, Urine Unit Converter

Urinary norepinephrine measures the amount of norepinephrine (also called noradrenaline) excreted in your urine over a set period, typically 24 hours. Norepinephrine is both a neurotransmitter and a hormone produced by the adrenal glands and sympathetic nerve endings.

A small but relatively constant fraction of circulating norepinephrine is excreted into the urine. Because levels in the blood fluctuate rapidly in response to stress, urine collection provides an integrated measurement representing average norepinephrine production over a longer period.

This test is commonly used alongside other catecholamine and metanephrine measurements to evaluate sympathetic nervous system activity and screen for certain tumors that produce excess catecholamines.

Norepinephrine is produced by the adrenal medulla (the inner portion of the adrenal glands) and by sympathetic nerve endings throughout the body. In the brain, it is synthesized primarily in the locus coeruleus. Norepinephrine is derived from the amino acid tyrosine through a series of enzymatic conversions involving dopamine as an intermediate.