Catecholamines, Total, Plasma Unit Converter

Total plasma catecholamines measures the combined concentration of three hormones in your blood: epinephrine (adrenaline), norepinephrine (noradrenaline), and dopamine. These are the chemical messengers your body releases during the "fight-or-flight" response.

Under normal resting conditions, norepinephrine makes up the largest share of circulating catecholamines, followed by epinephrine and then dopamine. Most labs report each component individually (fractionated catecholamines) in addition to the total.

This test is most commonly used to help diagnose catecholamine-secreting tumors such as pheochromocytoma or paraganglioma, and to evaluate disorders of the autonomic nervous system.

Epinephrine is produced primarily by the adrenal glands (the medulla), while most circulating norepinephrine comes from sympathetic nerve endings throughout the body. Dopamine is made in the brain, adrenal glands, and small amounts in the gastrointestinal tract and kidneys.