Serum or plasma mass concentration of 5-hydroxyindoleacetic acid (5-HIAA)
This test measures the amount of 5-hydroxyindoleacetic acid, a breakdown product of serotonin, in your blood. It helps assess serotonin metabolism, often used in evaluating conditions like carcinoid syndrome or serotonin-related disorders.
["This test may help diagnose or monitor conditions affecting serotonin production or metabolism."]
Key facts at a glance
- LOINC
- 78845-5
- Short code
- JWH-200 6-Hydroxyindole Ur Cfm-mCnc
- Synonyms
- JWH-200 6-Hydroxyindole Ur Cfm-mCnc
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- confirm
- Specimen volume
- 10 mL
- Stability
- Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms or a history suggestive of serotonin-related disorders, such as carcinoid tumors, serotonin syndrome, or other metabolic conditions. It could also be part of a broader evaluation for gastrointestinal issues or neurological symptoms linked to serotonin imbalance.
What to Expect Before the Test
No special preparation is typically required, but you may be asked to fast for a few hours before the blood draw if your test involves a fasting sample. Follow your provider’s instructions carefully to ensure accurate results.
What the Test Involves
A healthcare professional will collect a blood sample from a vein in your arm. This is usually done with minimal discomfort and takes a few minutes. The sample is then sent to a lab for analysis.
What the Results Mean
Results are interpreted based on your clinical picture, symptoms, and other test findings. Elevated levels may suggest conditions like carcinoid syndrome or excessive serotonin production, while lower levels might indicate metabolic or neurological concerns. Your provider will discuss the results with you.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated 5-HIAA levels in urine or blood can indicate conditions such as carcinoid tumors, which produce serotonin and other hormones. It may also help diagnose serotonin-related syndromes or assess serotonin metabolism in patients with neurological or gastrointestinal disorders. However, results alone are not definitive and should be evaluated alongside other clinical findings.
Short name
5-Hydroxyindoleacetic acid (5-HIAA) level
Frequently asked questions
How is this test usually done?
What are common reference ranges?
Can this test detect all serotonin-related conditions?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy