Catecholamines are hormones made by your adrenal glands, which are located on top of your kidneys. Examples include dopamine; norepinephrine; and epinephrine (this used to be called adrenalin or adrenaline).
Your adrenal glands send catecholamines into your blood when you're physically or emotionally stressed. They make you breathe faster, raise your blood pressure, and send more blood to major organs, like your brain, heart, and kidneys.
Your doctor may want to test your levels if he thinks you might have a rare tumor that's affecting your hormone levels. If you do, it could cause other problems, like high blood pressure, headaches, or a rapid heartbeat.
These kinds of tumors include:
- Pheochromocytoma tumors, which form in the middle of an adrenal gland
- Paraganglioma tumors, which form on the outside of an adrenal gland
- Neuroblastoma tumors, which are cancers that begin in nerve cells. These show up in your nervous system and typically affect infants and children under age 10
Most cases of high blood pressure aren't caused by tumors. But if you have other issues, like headaches, unusual heartbeat patterns, bone pain, weight loss, sweating, trouble walking or moving normally, or lumps in your stomach, your doctor may want to test your catecholamines to see if a tumor might be causing them.
If you have high levels of catecholamines in your blood, your doctor will do other tests to find out if you have a tumor. These might include:
- A computerized tomography (CT) scan: X-rays are taken from different angles and put together to make a more complete picture of certain areas.
- A magnetic resonance imaging (MRI) scan: Powerful magnets and radio waves are used to make detailed images of parts of your body.
- A radioisotope scan (or nuclear medicine test): A small amount of radioactive material, called a tracer, is put into a vein in your hand or arm. It goes to the area of your body your doctor wants a closer look at, and a special camera is used to take pictures.
Types of Catecholamine Tests
Catecholamines can be measured by a urine test or a blood test. Urine tests are more common, but your doctor may want to do both to get more information.
A urine catecholamines test measures the total amount in your urine over a 24-hour period. That's because hormone levels can go up and down during the day.
You'll pee into a special container every time you use the bathroom for 24 hours. You'll keep the container closed and store it in a cool place, like your refrigerator, during the test period. When you're done, you'll return it to your doctor or take it to a lab.
If you're collecting urine for your child, you'll use a collection bag -- a plastic bag with tape. The bag attaches to your child's skin (either around the penis for a boy or on either side of the vagina for a girl). As with the adult test, you'll empty the bag each time your child pees.
For a blood test, a nurse will take a sample of your blood and send it to a lab. For infants and very young children, the doctor may use a tool called a lancet to prick the skin. She'll then get a sample of blood in a small glass tube, on a slide, or on a test strip and send it to a lab for testing.
How to Prepare
Exercise and stress can affect catecholamines, so your doctor may recommend that you don't do any vigorous exercise and avoid stressful situations before and during your test.
Some foods also can increase your catecholamine levels. You shouldn't eat or drink the following for several days before your test:
- Coffee, tea, or any other caffeinated drinks
- Chocolate and cocoa of all kinds
- Citrus fruits, like oranges or lemons
- Vanilla (avoid anything that has vanilla extract or that's vanilla flavored)
Some medications, including ones used for diabetes, depression, and infections, can affect catecholamine levels, too. Tell your doctor about every prescription and over-the-counter medication you take as well as vitamins and other supplements.