WHAT ARE CATECHOLAMINES—URINE TEST?
Catecholamines are a group of hormones that are secreted from the adrenal medulla (epinephrine and norepinephrine) and are also released from nerve endings (epinephrine, norepinephrine, and dopamine). These hormones function in the fight-or-flight response, sympathetic nervous system functioning, blood pressure and hemodynamic controls, and response to stressors. Catecholamines are degraded and excreted by the kidneys and can be measured in random urine samples. In pheochromocytoma, the tumour secretes increased amounts of catecholamines, causing paroxysmal or persistent hypertension. Therefore 24-hour urine catecholamine levels are helpful in detecting paroxysmal secretion that occurs throughout the day and may be missed by random plasma levels.