5-Hydroxyindoleacetic Acid (HIAA), Urine
Ordering Recommendation

Use to diagnose carcinoid tumors and monitor disease.

Quantitative High Performance Liquid Chromatography - Tandem Mass Spectrometry
1-4 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Patients should abstain, if possible, from medications, over-the-counter drugs, and herbal remedies for at least 72 hours prior to the test. Foods rich in serotonin (avocados, bananas, eggplant, pineapple, plums, tomatoes, walnuts) and medications that may affect metabolism of serotonin must be avoided at least 72 hours before and during collection of urine for HIAA. 
24-hour or random urine. Refrigerate 24-hour specimens during collection. 
Specimen Preparation
Transfer 4 mL aliquot from a well-mixed 24-hour or random collection to an ARUP Standard Transport Tube. (Min: 1 mL) Record total volume and collection time interval on transport tube and test request form. 
Storage/Transport Temperature
Unacceptable Conditions
Any sample except urine. 
Please see Note for a more comprehensive list of dietary restrictions. 
Ambient: Unacceptable; Refrigerated: 1 week; Frozen: 2 months 
Reference Interval
Test Number
Reference Interval
 5-HIAA Urine - per 24h0.0-15.0 mg/d
 5-HIAA Urine - per volumeThe HIAA-to-creatinine ratio will be reported whenever the urine collection is random or other than 24 hours, or the urine volume is less than 400 mL/24 hours.

0-14 mg/g crt
 Creatinine, Urine - per 24h
3-8 years140-700 mg/d140-700 mg/d
9-12 years300-1300 mg/d300-1300 mg/d
13-17 years500-2300 mg/d400-1600 mg/d
18-50 years1000-2500 mg/d700-1600 mg/d
51-80 years800-2100 mg/d500-1400 mg/d
81 years and older600-2000 mg/d400-1300 mg/d

Interpretive Data
5-Hydroxyindoleacetic acid (5-HIAA) results are expressed as a ratio to creatinine excretion (mg/g CRT). HIAA mass per day (mg/d) is not reported if urine collection is random, other than 24 hours, or for a urine volume less than 400 mL/d. No reference interval is available for results reported in units of mg/L. Increased urine 5-HIAA concentration is common and may be the result of improper specimen collection, consumption of serotonin containing foods or dietary supplements, drug interference, or malabsorption syndromes. Significant elevation (ten times the upper reference limit) of urine 5-HIAA may indicate the presence of a carcinoid tumor.

Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Foods and medications associated with altered urinary HIAA results:

Decreased HIAA: Aspirin, chlorpromazine (Thorazine), corticotropin, dihydroxyphenylacetic acid, alcohol, gentisic acid, homogentisic acid, hydrazine derivatives, imipramine (Tofranil®), isocarboxazid (Marplan), keto acids, levodopa, MAO inhibitors, methenamine, methyldopa (Aldomet®), perchlorperazine, phenothiazines (Compazine®), promazine, promethazine (Mepergan®).

Increased HIAA:
Acetaminophen, acetanilide, caffeine, coumaric acid, diazepam (Valium®), ephedrine, fluorouracil, glycerol guaiacolate (Guaifenesin), melphalan (Alkeran®), mephenesin, methamphetamine (Desoxyn), methocarbamol (Robaxin®), naproxen, nicotine, phenacetin, phenmetrazine, phenobarbital, phentolamine, rauwolfia, reserpine.
Hotline History
Component Test Code*Component Chart NameLOINC
0020207Creatinine, Urine - per volume2161-8
0020208Creatinine, Urine - per 24h2162-6
00802385-HIAA Urine Interpretation44909-0
00803205-HIAA Urine - per 24h1695-6
00803215-HIAA Urine - per volume31203-3
00813435-HIAA Urine - ratio to CRT44288-9
0097110Total Volume19153-6
0097111Hours Collected30211-7
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
  • 5-HIAA
  • 5-OH-Indoleacetic Acid
  • Hydroxyindoleacetic Acid
  • Serotonin Metabolite