To help confirm or rule out a rare tumor of the adrenal gland called a pheochromocytoma or a rare tumor outside of the adrenal gland called a paraganglioma; these tumors (PPGL) produce excess catecholamines, which are broken down to metanephrines.
Catecholamines
After or along with plasma free metanephrines and/or urine metanephrines tests and when your healthcare practitioner needs additional information about a possible tumor that produces catecholamines
A 24-hour urine sample; sometimes a blood sample drawn from a vein
These tests are affected by certain drugs, foods, and stresses. Tell your healthcare practitioner about any medications you are taking and follow any preparation instructions you are given before sample collection. Although you may be seated for collection of the blood sample, it is recommended that you be lying down. Your healthcare practitioner or the collection site will instruct you as to their specific requirements.
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How is it used?
Catecholamines testing may be used in follow up to plasma free metanephrines and/or urine metanephrines testing to help confirm or rule out rare tumors called pheochromocytomas and paragangliomas. It also may be used to monitor for recurrence of these tumors. Pheochromocytomas and paragangliomas produce catecholamines in excess, so measuring the amount in the blood and/or urine may help detect the tumor.
The Endocrine Society recommends tests for plasma free metanephrines and urine metanephrines to help diagnose pheochromocytomas or paragangliomas. If results of those tests are inconclusive, then urine testing for catecholamines may be used to provide additional information. Blood catecholamine testing may sometimes be used, but it is not as reliable because the stress of having blood drawn can increase levels. However, your healthcare practitioner may select any one (or more than one) of these tests depending on your signs and symptoms, family history, and/or genetic profile.
- Urine catecholamines testing measures the total amount of catecholamines released into the urine in 24 hours. Since the hormone levels may fluctuate significantly during this period, the urine test may detect excess episodic production that is missed with the blood test.
- Catecholamine blood test may be useful when you have persistent hypertension or are currently experiencing a sudden burst (paroxysm) of hypertension. This is because the hormones do not stay long in the blood; they are used by the body and rapidly broken down (metabolized) and/or then eliminated.
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When is it ordered?
Catecholamines testing may be ordered when tests for plasma free metanephrines and/or urine metanephrines are inconclusive and a healthcare practitioner needs more information about a possible tumor that produces catecholamines. It may be ordered when you have sudden bursts (paroxysms) of specific signs and symptoms (especially If you are younger than age 40). Signs and symptoms may include:
- High blood pressure (hypertension), especially when you have hypertension that is not responding to treatment (people with PPGL are frequently resistant to conventional therapies)
- Severe headaches
- Sweating
- Flushing
- Rapid heart rate (palpitations)
- Tremors
The tests may also be ordered when an adrenal or neuroendocrine tumor is detected during a scan conducted for another purpose or if you have a strong personal or family history of pheochromocytoma.It may also be ordered at intervals when you have been previously treated for one of these tumors.
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What does the test result mean?
A high level of catecholamines in the blood and/or urine when you have signs and symptoms strongly suggests the presence of a tumor that produces catecholamines. It indicates that further investigation is needed. It is recommended that imaging studies be performed to locate the tumor once test results show clear evidence of such a tumor.
The test for catecholamines is very sensitive and false positives do occur. The test is affected by stress, drugs, smoking, and various foods such as caffeine-containing drinks and alcohol. If you have only moderately elevated levels, then your healthcare practitioner may re-evaluate your medications, diet, and stress level to look for interfering substances or conditions. Once these are resolved, you may then be tested again to determine whether the levels are still elevated and take appropriate action.
If catecholamine levels are elevated after you have been treated for such a tumor, then it is likely that either treatment was not fully effective or the tumor has returned and appropriate follow up is needed.
If the level of catecholamines is normal, then it is unlikely that you have a tumor that produces catecholamines. However, pheochromocytomas do not necessarily produce catecholamines at a constant rate. Therefore, if you have not had a recent episode of hypertension, your blood and urine catecholamine levels could be at normal or near normal levels even when a pheochromocytoma is present. If suspicion remains high, testing may be repeated.
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Is there anything else I should know?
While plasma and urine catecholamines tests can help detect and diagnose tumors that produce catecholamines, they cannot tell the location of the tumor, whether there is more than one, or whether or not the tumor is benign (although most are). The total amount of catecholamines produced will tend to increase as the tumor increases in size or number.
Although pheochromocytomas and paragangliomas are rare, 25% occur in the setting of a hereditary syndrome associated with alterations in specific genes. These genetic syndromes have thus been identified as carrying an increased tumor risk. Examples include MEN-1 and MEN-2 (Multiple Endocrine Neoplasia, types 1 and 2) syndromes. (For more information on these, see Genetics Home Reference: Multiple endocrine neoplasia.)
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Is there any way to prevent a pheochromocytoma from forming?
No, they can be detected and removed but not prevented. In most cases, the tumor is benign and, once it is removed, it will not recur.
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Is it really necessary to collect urine for 24 hours?
Yes, for accurate test results it is essential that all of the urine be collected. Catecholamines are released in varying amounts at varying times, so the one sample not included might be the one with the most hormones in it. For general instructions, read about the 24-hour urine collection.
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Can my state of mind really affect my test results?
Yes, because catecholamines are released from the adrenal glands in response to stress. If you are anxious or afraid, your catecholamines levels may be increased.

