5-Hydroxyindoleacetate

ChemistryAlso known as: 5OH-indoleacetate 24h Ur QlAlso known as: 5OH-indoleacetate 24h Ur-mCncAlso known as: 5OH-indoleacetate 24h Ur-mRateumol/L

Measures serotonin breakdown products in serum or plasma collection.

Normal Range
0 – 50 umol/L
umol/L
Abnormal Levels
Consult your provider
Specimen Type
Blood

Why This Biomarker Matters

Elevated 5-HIAA is a key marker for carcinoid syndrome. Early detection of carcinoid tumors can prevent serious complications affecting the heart and digestive system.

Understanding Your Results

Normal Range

0 – 50 umol/L

Overview

5-hydroxyindoleacetate (5-HIAA) is a breakdown product of serotonin measured in urine. Serotonin is a chemical messenger in your body that affects mood, digestion, and other functions. Elevated urinary 5-HIAA levels are primarily associated with carcinoid syndrome, a rare condition caused by neuroendocrine tumors that overproduce serotonin. This test is used to screen for and monitor carcinoid tumors, which can cause flushing, diarrhea, and heart valve problems.

Research & Evidence

1 publications

Dietary nitrate drives gastritis by modulating gastric microbiota and metabolites.
Cancer Biol Med · 2026
PMID: 42046343

Research data from MEDLINE/PubMed · 1 articles

Technical Information (LOINC Codes)

Standardized laboratory codes for this biomarker

50149-4Primary
5-Hydroxyindoleacetate [Moles/volume] in Serum or Plasma
nmol/L
15009-4
5-Hydroxyindoleacetate [Moles/volume] in Urine
umol/L
12172-3
5-Hydroxyindoleacetate [Presence] in 24 hour Urine
14573-0
5-Hydroxyindoleacetate [Moles/time] in 24 hour Urine
umol/(24.h)
1693-1
5-Hydroxyindoleacetate [Mass/volume] in Serum or Plasma
mg/mL
1694-9
5-Hydroxyindoleacetate [Mass/volume] in Urine
ug/mL
48168-9
5-Hydroxyindoleacetate [Presence] in Urine
31203-3
5-Hydroxyindoleacetate [Mass/volume] in 24 hour Urine
mg/mL
1695-6
5-Hydroxyindoleacetate [Mass/time] in 24 hour Urine
mg/(24.h)
74769-1
5-Hydroxyindoleacetate [Moles/volume] in Platelet rich plasma
nmol/L
1692-3
5-Hydroxyindoleacetate [Mass/volume] in Cerebral spinal fluid
mg/mL
25971-3
5-Hydroxyindoleacetate [Moles/volume] in 24 hour Urine
umol/L
47544-2
5-Hydroxyindoleacetate [Moles/volume] in Cerebral spinal fluid
nmol/L
72820-4
5-Hydroxyindoleacetate [Mass/volume] in Urine by Confirmatory method
ng/mL

Available Lab Tests

Order tests that measure this biomarker

Urinary Organic Acids

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