Test Id : HIAA
5-Hydroxyindoleacetic Acid, 24 Hour, Urine
Useful For
Suggests clinical disorders or settings where the test may be helpful
Biochemical diagnosis and monitoring of intestinal carcinoid syndrome using 24-hour urine specimens
Method Name
A short description of the method used to perform the test
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
5-HIAA (5-Hydroxyindolacetic Acid)
5-OH-Indoleacetic Acid
Carcinoid Syndrome
HIAA (Hydroxyindoleacetic Acid)
Serotonin Metabolite
Specimen Type
Describes the specimen type validated for testing
Urine
Ordering Guidance
This test is the preferred test for measurement of 5-hydroxyindoleacetic acid concentrations. If a random urine collection is preferred, order HIAAR / 5-Hydroxyindoleacetic Acid, Random, Urine.
Necessary Information
1. Collection duration and urine volume in milliliters are required.
2. Patient's age and sex are required.
ORDER QUESTIONS AND ANSWERS
| Question ID | Description | Answers |
|---|---|---|
| TM35 | Collection Duration | |
| VL33 | Urine Volume |
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Patient Preparation:
1. Some medications could interfere with test results. If medically feasible, for 48 hours before specimen collection, patient should not take the following medications:
-Acetaminophen (Tylenol or generic versions)
-Tryptophan containing supplements
2. For 48 hours prior to, as well as during, the urine collection, the patient should limit the following to one serving per day:
-Fruits
-Vegetables
-Nuts
-Caffeinated beverages or foods
Supplies: Urine Tubes, 10 mL (T068)
Container/Tube: Plastic, 10-mL urine tube
Specimen Volume: 5 mL
Collection Instructions:
1. Add 25 mL of 50% acetic acid as preservative at start of collection. Use 15 mL of 50% acetic acid for children younger than 5 years.
2. Collect a 24-hour urine specimen.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Urine Preservative Collection Options
Note: The addition of preservative must occur prior to beginning the collection.
| Ambient (no additive) | No |
| Refrigerate (no additive) | OK |
| Frozen (no additive) | OK |
| 50% Acetic Acid | Preferred |
| Boric Acid | OK |
| Diazolidinyl Urea | No |
| 6M Hydrochloric Acid | OK |
| 6M Nitric Acid | OK |
| Sodium Carbonate | OK |
| Toluene | OK |
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
1 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 56 days | |
| Frozen | 365 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Biochemical diagnosis and monitoring of intestinal carcinoid syndrome using 24-hour urine specimens
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
5-Hydroxyindoleacetic acid (5-HIAA) is the major metabolite of serotonin and is excreted in the urine. Intestinal carcinoid tumors, along with neuroendocrine tumors, can produce excess amounts of 5-HIAA and serotonin, especially in individuals with carcinoid syndrome. Carcinoid syndrome is characterized by carcinoid tumors, flushing, heart disease, and hepatomegaly.
Measurement of 5-HIAA in a 24-hour urine specimen can diagnose carcinoid disease with a high specificity.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
| 5-HIAA, mg/24 hour 99th percentile cutoff | ||
| Age | Female | Male |
| < or =23 months | < or =2.7 | < or =2.3 |
| 24-35 months | < or =3.0 | < or =2.6 |
| 3 years | < or =3.2 | < or =2.9 |
| 4 years | < or =3.4 | < or =3.2 |
| 5 years | < or =3.6 | < or =3.6 |
| 6 years | < or =3.8 | < or =3.9 |
| 7 years | < or =4.0 | < or =4.2 |
| 8 years | < or =4.2 | < or =4.5 |
| 9 years | < or =4.5 | < or =4.8 |
| 10 years | < or =4.7 | < or =5.1 |
| 11 years | < or =4.9 | < or =5.3 |
| 12 years | < or =5.2 | < or =5.6 |
| 13 years | < or =5.4 | < or =5.8 |
| 14 years | < or =5.6 | < or =6.1 |
| 15 years | < or =5.7 | < or =6.3 |
| 16 years | < or =5.9 | < or =6.4 |
| 17 years | < or =6.0 | < or =6.6 |
| 18 years | < or =6.0 | < or =6.7 |
| 19 years | < or =6.1 | < or =6.8 |
| 20 years | < or =6.1 | < or =6.9 |
| 21 years | < or =6.2 | < or =6.9 |
| 22 years | < or =6.2 | < or =7.0 |
| 23 years | < or =6.2 | < or =7.0 |
| 24 years | < or =6.3 | < or =7.1 |
| 25 years | < or =6.3 | < or =7.2 |
| 26 years | < or =6.3 | < or =7.2 |
| 27 years | < or =6.4 | < or =7.3 |
| 28 years | < or =6.4 | < or =7.4 |
| 29 years | < or =6.5 | < or =7.5 |
| 30 years | < or =6.6 | < or =7.5 |
| 31 years | < or =6.6 | < or =7.6 |
| 32 years | < or =6.7 | < or =7.7 |
| 33 years | < or =6.8 | < or =7.7 |
| 34 years | < or =6.8 | < or =7.8 |
| 35 years | < or =6.9 | < or =7.9 |
| 36 years | < or =6.9 | < or =7.9 |
| 37 years | < or =7.0 | < or =8.0 |
| 38 years | < or =7.0 | < or =8.1 |
| 39 years | < or =7.0 | < or =8.2 |
| 40 years | < or =7.1 | < or =8.2 |
| 41 years | < or =7.1 | < or =8.3 |
| 42 years | < or =7.2 | < or =8.4 |
| 43 years | < or =7.3 | < or =8.5 |
| 44 years | < or =7.4 | < or =8.6 |
| 45 years | < or =7.4 | < or =8.7 |
| 46 years | < or =7.5 | < or =8.8 |
| 47 years | < or =7.6 | < or =8.9 |
| 48 years | < or =7.6 | < or =9.0 |
| 49 years | < or =7.7 | < or =9.1 |
| 50 years | < or =7.7 | < or =9.2 |
| 51 years | < or =7.8 | < or =9.3 |
| 52 years | < or =7.8 | < or =9.4 |
| 53 years | < or =7.9 | < or =9.5 |
| 54 years | < or =8.0 | < or =9.6 |
| 55 years | < or =8.1 | < or =9.7 |
| 56 years | < or =8.1 | < or =9.7 |
| 57 years | < or =8.2 | < or =9.8 |
| 58 years | < or =8.3 | < or =9.8 |
| 59 years | < or =8.3 | < or =9.8 |
| 60 years | < or =8.3 | < or =9.9 |
| 61 years | < or =8.3 | < or =9.9 |
| 62 years | < or =8.4 | < or =9.9 |
| 63 years | < or =8.4 | < or =10.0 |
| 64 years | < or =8.4 | < or =10.0 |
| 65 years | < or =8.4 | < or =10.0 |
| 66 years | < or =8.5 | < or =10.1 |
| 67 years | < or =8.5 | < or =10.1 |
| 68 years | < or =8.5 | < or =10.1 |
| 69 years | < or =8.5 | < or =10.2 |
| 70 years | < or =8.5 | < or =10.2 |
| 71 years | < or =8.6 | < or =10.2 |
| 72 years | < or =8.6 | < or =10.2 |
| 73 years | < or =8.5 | < or =10.1 |
| 74 years | < or =8.5 | < or =10.1 |
| 75 years | < or =8.6 | < or =10.1 |
| 76 years | < or =8.6 | < or =10.0 |
| 77 years | < or =8.6 | < or =10.0 |
| 78 years | < or =8.6 | < or =10.0 |
| 79 years | < or =8.6 | < or =10.0 |
| 80 years | < or =8.7 | < or =9.9 |
| 81 years | < or =8.7 | < or =9.9 |
| 82 years | < or =8.7 | < or =9.9 |
| 83 years | < or =8.7 | < or =9.9 |
| 84 years | < or =8.7 | < or =9.9 |
| 85 years | < or =8.6 | < or =9.8 |
| 86 years | < or =8.5 | < or =9.8 |
| 87 years | < or =8.4 | < or =9.7 |
| 88 years | < or =8.3 | < or =9.7 |
| 89 years | < or =8.1 | < or =9.5 |
| 90 years | < or =7.9 | < or =9.4 |
| 91 years | < or =7.6 | < or =9.2 |
| 92 years | < or =7.4 | < or =9.0 |
| 93 years | < or =7.1 | < or =8.8 |
| 94 years | < or =7.0 | < or =8.7 |
| = 95 years | < or =6.9 | < or =8.6 |
For SI unit Reference Values, see www.mayocliniclabs.com/order-tests/si-unit-conversion.html
Interpretation
Provides information to assist in interpretation of the test results
If pharmacological and dietary artifacts have been ruled out, an elevated excretion of 5-hydroxyindoleacetic acid is a probable indicator of the presence of a serotonin-producing tumor.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Intake of food with a high content of serotonin (avocados, dates, eggplant, all fruit [including bananas, cantaloupe, grapefruit, kiwi fruit, melons, pineapple, plantains, plums], all nuts [including hickory nuts, butternuts, pecans, walnuts], and tomatoes and tomato products) within 48 hours of the urine collection could result in falsely elevated 5-hydroxyindoleacetic acid (5-HIAA) excretion.
Numerous drugs affect the excretion of 5-HIAA by different mechanisms, including increased serotonin synthesis, metabolism, and release and inhibition of uptake. The following medications can interfere with 5-HIAA results.
-Acetaminophen (Tylenol or generic versions)
-Tryptophan containing supplements
Patient should also avoid caffeinated beverages, such as tea and coffee, or caffeinated foods, such as dark chocolate, for 48 hours before and during specimen collection.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Grimaldi F, Fazio N, Attanasio R, et al. Italian Association of Clinical Endocrinologists (AME) position statement: a stepwise clinical approach to the diagnosis of gastroenteropancreatic neuroendocrine neoplasms. J Endocrinol Invest. 2014;37(9):875-909. doi:10.1007/s40618-014-0119-0
2. Vinik A, Hughes MS. Feliberti E, et al. Carcinoid tumors. In: Feingold KR, Anawalt B, Boyce A, et al, eds. Endotext [Internet]. MDText.com, Inc; 2000. Updated August 25, 2023. Accessed April 1, 2025. Available at www.ncbi.nlm.nih.gov/books/NBK279162/
3. Shah D, Mandot A, Cerejo C, Amarapurkar D, Pal A. The outcome of primary hepatic neuroendocrine tumors: A single-center experience. J Clin Exp Hepatol. 2019;9(6):710-715. doi:10.1016/j.jceh.2019.08.002
4. Perry D, Hayek SS. Carcinoid heart disease: A guide for clinicians. Cardiol Clin. 2019;37(4):497-503. doi:10.1016/j.ccl.2019.07.014
5. Degnan AJ, Tocchio S, Kurtom W, Tadros SS. Pediatric neuroendocrine carcinoid tumors: Management, pathology, and imaging findings in a pediatric referral center. Pediatr Blood Cancer. 2017;64(9). doi:10.1002/pbc.26477
6. Corcuff JB, Chardon L, El Hajji Ridah I, Brossaud J. Urinary sampling for 5HIAA and metanephrines determination: revisiting the recommendations. Endocr Connect. 2017;6(6):R87-R98. doi:10.1530/EC-17-0071
Method Description
Describes how the test is performed and provides a method-specific reference
5-Hydroxyindoleacetic acid (5-HIAA) is measured by solid phase extraction of an aliquot from a 24-hour urine collection and liquid chromatography tandem mass spectrometry analysis. 5-HIAA is quantitated using a custom synthesized stable isotope labeled internal standard (d6-5-HIAA) from calibration over a concentration range 0.5 to 150 mg/L.(Kroll CA, Magera MJ, Helgeson JK, Mattern D, Rinaldo P. A liquid chromatographic-tandem mass spectrometric method for the determination of 5-hydroxyindole-3-acetic acid in urine. Clin Chem. 2002;48[11]:2049-2051; Calanchini M, Tadman M, Krogh J, Fabbri A, Grossman A, Shine B. Measurement of urinary 5-HIAA: correlation between spot versus 24-h urine collection. Endocr Connect. 2019;8[8]:1082-1088)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.
CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
83497
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| HIAA | 5-Hydroxyindoleacetic Acid, U | 1695-6 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 9248 | 5-Hydroxyindoleacetic Acid, U | 1695-6 |
| TM35 | Collection Duration | 13362-9 |
| VL33 | Urine Volume | 3167-4 |