Catecholamines in Blood

A test for catecholamines measures the amount of the hormones epinephrine, norepinephrine, metanephrine, and dopamine in the blood. 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" reactions.

The 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.

Catecholamines 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 kidneys.

Certain rare tumors (such as a pheochromocytoma) can increase the amount of catecholamines in the blood. This causes high blood pressure, excessive sweating, headaches, fast heartbeats (palpitations), and tremors.

A catecholamine test is done to help diagnose a tumor in the adrenal glands called a pheochromocytoma. Catecholamine levels in the blood can change quickly, so it may be hard to find high values in a single blood sample. But a special compound, metanephrine, may be found in the blood, which may mean a pheochromocytoma is present. Doctors may want to do a urine test that shows catecholamine levels over 24 hours.

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 chocolate
• Amines. These are found in bananas, walnuts, avocados, fava beans, cheese, beer, and red wine.
• Any foods or fluids with vanilla
• Licorice
• Aspirin

You may be asked to not eat or drink anything for 10 hours before this test. Do not use tobacco for 4 hours before the blood test.

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

Having a blood sample taken can cause stress. This may increase catecholamine levels. Be sure to keep warm, because being cold can also increase your catecholamine levels. Ask for a blanket if you feel cold.

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?).

The health professional drawing your blood will:

• Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
• Clean the needle site with alcohol.
• Put the needle into the vein. More than one needle stick may be needed.
• Attach a tube to the needle to fill it with blood.
• Remove the band from your arm when enough blood is collected.
• Put a gauze pad or cotton ball over the needle site as the needle is removed.
• Put pressure to the site and then a bandage.

The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.

There is very little chance of a problem from having blood sample taken from a vein.

• You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
• In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. A warm compress can be used several times a day to treat this.
• Ongoing bleeding can be a problem for people with bleeding disorders. Aspirin, warfarin (Coumadin), and other blood-thinning medicines can make bleeding more likely. If you have bleeding or clotting problems, or if you take blood-thinning medicine, tell your doctor before your blood sample is taken.

A test for catecholamines measures the amount of epinephrine, norepinephrine, and dopamine in the blood. These catecholamines are made by nerve tissue, the brain, and the adrenal glands.

Normal

Normal values may vary widely from lab to lab.

High values

• High levels of catecholamines, vanillylmandelic acid (VMA), or metanephrine can mean an adrenal gland tumor (pheochromocytoma) or another type of tumor that makes catecholamines is present.
• High levels may also be seen with any major stress, such as burns, a whole-body infection (sepsis), illness, surgery, and traumatic injury.
• Many blood pressure medicines can also cause high catecholamine levels.

Low values

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

Reasons you may not be able to have the test or why the results may not be helpful include:

• Doing physical exercise.
• Having extreme emotional stress.
• Having surgery, injury, or illness.
• Taking certain medicines, such as aspirin, nitroglycerin, tricyclic antidepressants, tetracycline, theophylline, and some blood pressure medicines.
• Using nicotine, alcohol (ethanol) or cocaine.
• Taking nonprescription cough, cold, or sinus medicines.
• Eating or drinking foods with caffeine.

• This test is not done very often. The 24-hour urine test is better for finding high levels of catecholamines than a blood test. For more information on a catecholamine urine test, see the medical test Catecholamines in Urine.
• Another test, called the clonidine suppression test, may be done to find out whether high blood pressure is caused by an adrenal gland tumor. The clonidine suppression test measures your blood catecholamine levels before and after you take a small dose of the high blood pressure medicine clonidine (Catapres). If a tumor is present, clonidine will not cause your catecholamine levels to change. If your high blood pressure is caused by other factors, clonidine will cause your catecholamine levels to go down.