Test Overview

Catecholamines (say "kat-uh-KOH-luh-meens") are hormones made mostly by your adrenal glands as a reaction to stress.

When you feel stressed, these hormones increase heart rate, blood pressure, breathing rate, muscle strength, and mental alertness. They also lower the amount of blood that goes to the skin and intestines. They increase blood going to the major organs, such as the brain, heart, and kidneys. This helps your body prepare for "fight-or-flight" reactions.

Your body breaks down these hormones and passes them into your urine. This test measures how much of these hormones are in your urine over a 24-hour period.

Why It Is Done

A catecholamines test is done to help diagnose a rare tumour in the adrenal glands called a pheochromocytoma.

Tumours like this can cause your adrenal glands to release too many hormones. And that can cause high blood pressure, excessive sweating, headaches, fast heartbeats, and tremors.

How To Prepare

You may be asked to avoid certain foods and fluids for 2 to 3 days before the test. They include:

• Caffeine, such as coffee, tea, cocoa, and chocolate.
• Amines. These are found in bananas, walnuts, avocados, fava beans, cheese, beer, and red wine.
• Any foods or fluids with vanilla.
• Licorice.

Do not use tobacco at all during the 24-hour urine collection.

Be sure to keep warm during the 24 hours. Being cold can raise your catecholamine levels.

Drink plenty of fluids during the 24 hours to avoid dehydration.

Your doctor may ask you to stop certain medicines, such as blood pressure medicines, before the test. Do not take cold or allergy remedies, aspirin, or diet pills for 2 weeks before the test.

How It Is Done

This test is usually done at home. You must collect all the urine you produce in a 24-hour period.

• When you first get up in the morning, urinate into the toilet. Don't save this urine. This marks the start of your 24-hour period.
• For the next 24 hours, collect all your urine. Your doctor or lab will give you a large container to store it in. Urinate into a separate small, clean container. Then pour the urine into the large container. Don't touch the inside of the containers with your fingers.
• Keep the large container in the refrigerator.
• Empty your bladder for the last time at or just before the end of the 24-hour period. Add this urine to the large container, and write down the time.
• Do not get toilet paper, pubic hair, stool (feces), menstrual blood, or anything else in your urine sample.

How It Feels

This test usually doesn't cause any pain or discomfort.

Risks

There are no known risks from having this test.

Results

Normal

Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.

High values

• High levels of free catecholamines, vanillylmandelic acid (VMA), or metanephrine can mean that an adrenal gland tumour or other type of tumour is present.
• Any major stress, such as burns, a whole-body infection (sepsis), illness, surgery, or traumatic injury, can cause high levels.
• Many blood pressure medicines can also cause high levels.

Low values

Low values may be caused by diabetes or some nervous system problems.