The test may be useful as a follow-up test to urine metanephrine or plasma free metanephrines for confirming the diagnosis of adrenal gland tumours: pheochromocytomas and paragangliomas in individuals with symptoms. It may also be recommended to monitor the progress of the treatment of the disorder.
The adrenal glands are responsible for the production of the catecholamines hormones, as a response to stress. They alert the person experiencing stress by increasing the blood flow to the brain, heart and the kidneys, preparing the person for an instant fight-or-flight reaction. The catecholamines thus increase breathing, heartbeats, alertness, blood pressure and muscle strength and lower the blood flow to the skin. These hormones are broken down by the body and are eliminated through urine. Therefore, a 24-hour urinary catecholamine test is used to measure the levels of these hormones in a urine sample.