calculated urine norepinephrine level absolute change in urine norepinephrine level 2013-06-14T16:19:20Z CMO:0001634 JSmith The difference in the amount of norepinephrine, a catecholamine hormone and neurotransmitter, secreted by the adrenal medulla and the nerve endings of the sympathetic nervous system, that causes vasoconstriction and increases heart rate, blood pressure, and blood sugar level, in a specified sample of urine, the fluid waste product excreted by the kidneys, between two points in time or two conditions expressed as the result of the subtraction in and of itself without comparison by ratio with another quantity. The term "absolute change" refers to the subtraction of one value from another, as opposed to a dissimilarity of two values expressed as a ratio or as a percentage. In this context it is not intended to necessarily imply the difference expressed as an absolute value |n|, that is, the numeric value of the difference without regard to its sign. VT:0010605 absolute change in urine noradrenalin level clinical_measurement_ontology