Site Map

5-HIAA urine test

HIAA; 5-hydroxyindole acetic acid; Serotonin metabolite

5-HIAA is a urine test that measures the amount of 5-hydroxyindoleacetic acid (5-HIAA). 5-HIAA is a breakdown product of a hormone called serotonin.

This test tells how much 5-HIAA the body is producing. It is also a way to measure how much serotonin is in the body.

I Would Like to Learn About:

How the Test is Performed

A 24-hour urine sample is needed. You'll need to collect your urine over 24 hours in a container provided by the laboratory. Your health care provider will tell you how to do this. Follow instructions exactly.

How to Prepare for the Test

Your provider will instruct you, if necessary, to stop taking medicines that may interfere with the test.

Medicines that can increase 5-HIAA measurements include acetaminophen (Tylenol), acetanilide, phenacetin, glyceryl guaiacolate (found in many cough syrups), methocarbamol, and reserpine.

Medicines that can decrease 5-HIAA measurements include heparin, isoniazid, levodopa, monoamine oxidase inhibitors, methenamine, methyldopa, phenothiazines, and tricyclic antidepressants.

You will be told not to eat certain foods for 3 days before the test. Foods that can interfere with 5-HIAA measurements include plums, pineapples, bananas, eggplant, tomatoes, avocados, and walnuts.

How the Test will Feel

The test involves only normal urination, and there is no discomfort.

Why the Test is Performed

This test measures the level of 5-HIAA in the urine. It is often done to detect certain tumors in the digestive tract (carcinoid tumors) and to track a person's condition.

The urine test may also be used to diagnose a disorder called systemic mastocytosis and some tumors of the hormone.

Normal Results

The normal range is 2 to 9 mg/24h (10.4 to 46.8 µmol/24h).

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results may be due to:

Risks

There are no risks with this test.

Related Information

Serotonin blood test
Tryptophan
Platelet count

References

Chernecky CC, Berger BJ. H. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:660-661.

Hande KR. Neuroendocrine tumors and the carcinoid syndrome. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 232.

BACK TO TOP

Review Date: 7/26/2018  

Reviewed By: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

ADAM Quality Logo

A.D.A.M., Inc. is accredited by URAC, for Health Content Provider (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics. This site complies with the HONcode standard for trustworthy health information: verify here.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2020 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.