A test for catecholamines measures the
amount of the
hormones epinephrine, norepinephrine, metanephrine, and dopamine
in the urine. These catecholamines are made by
nerve tissue , the brain, and the
adrenal glands. Catecholamines help the body respond
to stress or fright and prepare the body for "fight-or-flight"
adrenal glands make large amounts of catecholamines as a reaction to stress. The
main catecholamines are epinephrine (adrenaline), norepinephrine
(noradrenaline), and dopamine. They break down into vanillylmandelic acid (VMA)
and metanephrine, which are passed in the urine.
increase heart rate, blood pressure, breathing rate, muscle strength, and
mental alertness. They also lower the amount of blood going to the skin and
increase blood going to the major organs, such as the brain, heart, and
Certain rare tumors (such as a
pheochromocytoma) can increase the amount of
catecholamines in the blood and urine. The increased amount can cause high
blood pressure, excessive sweating, headaches, fast heartbeats (palpitations),
Why It Is Done
catecholamine test is done to help diagnose a tumor in
the adrenal glands called a pheochromocytoma.
How To Prepare
You may be asked to avoid the following
foods and fluids for 2 to 3 days before having this test:
- Caffeine, such as coffee, tea, cocoa, and
- Amines. These are found in bananas, walnuts, avocados,
fava beans, cheese, beer, and red wine.
- Any foods or fluids with
Do not use tobacco at all during the 24-hour urine
Be sure to keep warm during the 24-hour urine test
because being cold can increase your catecholamine levels.
plenty of fluids during the 24-hour time period to avoid
Many medicines may change
the results of this test. Be sure to tell your doctor about all the
nonprescription and prescription medicines you take.
Your doctor may ask you to stop certain medicines, such as blood
pressure medicines, before the test. Do not take cold or allergy remedies,
including aspirin, or nonprescription diet pills for 2 weeks before the
Talk to your doctor about any concerns you have regarding
the need for the test, its risks, how it will be done, or what the results will
mean. To help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).
How It Is Done
24 hour urine sample
- You start collecting your urine in the morning.
When you first get up, empty your bladder but do not save this urine. Write
down the time that you urinated to mark the beginning of your 24-hour
- For the next 24 hours, collect all your urine.
Your doctor or lab will usually provide you with a large container that holds
about 1 gal (4 L). The
container has a small amount of preservative in it. Urinate into a small, clean
container and then pour the urine into the large container. Do not touch the
inside of the container with your fingers.
- Keep the large container
in the refrigerator for the 24 hours.
- Empty your bladder for the
final time at or just before the end of the 24-hour period. Add this urine to
the large container and record the time.
- Do not get toilet paper,
pubic hair, stool (feces), menstrual blood, or other foreign matter in the