5-Hydroxyindoleacetic acid (5HIAA) is a breakdown product of serotonin that is excreted in the urine. Serotonin is a hormone found at high levels in many body tissues. Serotonin and 5HIAA are produced in excess amounts by carcinoid tumors, and levels of these substances may be measured in the urine to test for carcinoid tumors.
5-Hydroxyindoleacetic acid is found to be associated with:
- Aromatic l-amino acid decarboxylase deficiency an inherited disorder that affects the way signals are passed between certain cells in the nervous system.)
- Celiac disease (an autoimmune disorder where the ingestion of gluten leads to damage in the small intestine)
- Sepiapterin reductase deficiency (a condition characterized by movement problems)
- What are normal levels?
Normal results are 3 to 15 milligrams (mg) of 5-HIAA over 24 hours.
Women generally have lower levels than men.
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. Proper preparation before the test is essential. Medication and dietary restrictions are required to prevent false-positive results. If clinically feasible, discontinue the following medications at least 48 hours before specimen collection.
- Acetaminophen (Tylenol or generic versions)
- Aspirin
- Antihistamines
- Cough syrups
- Cold and flu medications
One should also avoid caffeinated beverages such as tea and coffee or caffeinated foods for 48 hours before and during specimen collection.
Certain medicines can raise or lower your 5-HIAA levels. These include:
- Aspirin
- Acetaminophen
- Ethyl alcohol
- Some antidepressants
- Cough medicines or antihistamines
- Medicines to relax muscles
References:
- Urinary sampling for 5HIAA and metanephrines determination: revisiting the recommendations, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5527357/
- Guidelines for the diagnosis and management of carcinoid tumours. Part 1: the gastrointestinal tract. A statement from a Canadian National Carcinoid Expert Group. (https://www.ncbi.nlm.nih.gov/pubmed/17576444)
- A single fasting plasma 5-HIAA value correlates with 24-hour urinary 5-HIAA values and other biomarkers in midgut neuroendocrine tumors (NETs). (https://www.ncbi.nlm.nih.gov/pubmed/23160483)
- Aromatic l-amino acid decarboxylase deficiency, https://ghr.nlm.nih.gov/condition/aromatic-l-amino-acid-decarboxylase-deficiency
- WHAT IS CELIAC DISEASE?, https://celiac.org/celiac-disease/understanding-celiac-disease-2/what-is-celiac-disease/
- Sepiapterin reductase deficiency, https://ghr.nlm.nih.gov/condition/sepiapterin-reductase-deficiency
Low 5-HIAA indicates inadequate production of serotonin. Symptoms include: constipation, depression, fatigue, insomnia, attention deficit and behavioral disorders.
Lower levels of 5-HIAA may mean you have:
- Depression
- Migraines
- What might affect the test results?
Foods and medications associated with decreased urinary HIAA results:
- 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®)
Understand and improve your laboratory results with our health dashboard.
Upload your lab reports and get your interpretation today.
Our technology helps to understand, combine, track, organize, and act on your medical lab test results.
High 5-HIAA can be caused by SSRI medication, 5-HTP supplementation, increased release of serotonin from the central nervous system, digestive system or platelets. Very high 5-HIAA levels can ironically indicated a tryptophan deficiency, as this may cause an increased conversion of tryptophan to serotonin.
Higher levels of 5-HIAA may mean you have:
- Carcinoid tumors
- Noncarcinoid tumors
- Cystic fibrosis
- Malabsorption
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.
Eating certain foods containing serotonin can raise 5-HIAA levels. These foods include:
- Cheese
- Bananas
- Pineapple
- Kiwi
- Plums
- Tomatoes
- Eggplant
- Avocados
- Certain nuts, including walnuts and pecans
Strenuous exercise can also raise your 5-HIAA levels.
Foods and medications associated with increased urinary HIAA results:
- 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
Interpret Your Lab Results
Upload your lab report, and we'll interpret and provide you with recommendations today.
Get Started
Monthly plan
Annual plan
Own it for life
Our exclusive data entry service is a convenient way to get your results into your private dashboard. Simply attach an image or a file of your lab test results, and one of our qualified data entry team members will add the results for you. We support all sorts of files, whether PDFs, JPGs, or Excel. This service is excellent whether you have a lot of reports to upload or are too busy to do the data entry yourself.
We strive to make the data entry process easy for you. Whether by offering dozens of templates to choose from that pre-populate the most popular laboratory panels or by giving you instant feedback on the entered values. Our data entry forms are an easy, fast, and convenient way to enter the reports yourself. There is no limit on how many lab reports you can upload.
$15 /month
billed every month
Most popular
Data entry included
$79 /year
$6.60/month billed annually
Data entry included
$250 /once
own it for life
Are You a Health Professional?
Get started with our professional plan
Welcome to Healthmatters Pro.
Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more
Pro Monthly Plus
for health professionals
$75 per month
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.
2-Hydroxybutyric, 2-Hydroxybutyric (Males Age 13 and Over), 2-Hydroxyhippuric, 2-Hydroxyhippuric (Females Under Age 13), 2-Hydroxyhippuric (Males Age 13 and Over), 2-Hydroxyisocaproic, 2-Hydroxyisocaproic (Males Age 13 and Over), 2-Hydroxyisovaleric, 2-Hydroxyisovaleric (Males Age 13 and Over), 2-Hydroxyphenylacetic, 2-Hydroxyphenylacetic (Males Age 13 and Over), 2-Oxo-4-methiolbutyric, 2-Oxo-4-methiolbutyric (Males Age 13 and Over), 2-Oxoglutaric, 2-Oxoglutaric (Males Age 13 and Over), 2-Oxoisocaproic, 2-Oxoisocaproic (Males Age 13 and Over), 2-Oxoisovaleric, 2-Oxoisovaleric (Males Age 13 and Over), 3-Hydroxy-3-methylglutaric (HMG), 3-Hydroxy-3-methylglutaric (Males Age 13 and Over), 3-Hydroxybutyric, 3-Hydroxybutyric (Males Age 13 and Over), 3-Hydroxyglutaric, 3-Hydroxyglutaric (Males Age 13 and Over), 3-Indoleacetic, 3-Indoleacetic (Males Age 13 and Over), 3-Methyl-2-oxovaleric, 3-Methyl-2-oxovaleric (Males Age 13 and Over), 3-Methylglutaconic, 3-Methylglutaconic (Males Age 13 and Over), 3-Methylglutaric, 3-Methylglutaric (Females Under Age 13), 3-Methylglutaric (Males Age 13 and Over), 3-Oxoglutaric, 3-Oxoglutaric (Males Age 13 and Over), 3-Oxoglutaric (Males Under Age 13), 4-Cresol, 4-Cresol (Males Age 13 and Over), 4-Hydroxybenzoic, 4-Hydroxybenzoic (Males Age 13 and Over), 4-Hydroxybutyric, 4-Hydroxybutyric (Females Under Age 13), 4-Hydroxybutyric (Males Age 13 and Over), 4-Hydroxyhippuric, 4-Hydroxyhippuric (Males Age 13 and Over), 4-Hydroxyphenylacetic, 4-Hydroxyphenylacetic (Females Under Age 13), 4-Hydroxyphenylacetic (Males Age 13 and Over), 4-Hydroxyphenyllactic, 4-Hydroxyphenyllactic (Males Age 13 and Over), 5-Hydroxyindoleacetic (5-HIAA), 5-Hydroxyindoleacetic (5-HIAA) (Males Age 13 and Over), 5-Hydroxymethyl-2-furoic, 5-Hydroxymethyl-2-furoic (Males Age 13 and Over), 5-Hydroxymethyl-2-furoic (Males Under Age 13), Acetoacetic, Acetoacetic (Males Age 13 and Over), Aconitic, Aconitic (Males Age 13 and Over), Adipic, Adipic (Males Age 13 and Over), Arabinose, Arabinose (Females Under Age 13), Arabinose (Males Age 13 and Over), Arabinose (Males Under Age 13), Ascorbic, Ascorbic (Males Age 13 and Over), Ascorbic (Males Under Age 13), Carboxycitric, Carboxycitric (Males Age 13 and Over), Citramalic, Citramalic (Males Age 13 and Over), Citric, Citric (Males Age 13 and Over), DHPPA (Beneficial Bacteria), DHPPA (Beneficial Bacteria) (Males Age 13 and Over), Dihydroxyphenylacetic (DOPAC), Dihydroxyphenylacetic (DOPAC) (Females Under Age 13), Dihydroxyphenylacetic (DOPAC) (Males Age 13 and Over), Dihydroxyphenylacetic (DOPAC) (Males Under Age 13), Ethylmalonic, Ethylmalonic (Males Age 13 and Over), Fumaric, Fumaric (Males Age 13 and Over), Furan-2,5-dicarboxylic, Furan-2,5-dicarboxylic (Males Age 13 and Over), Furancarbonylglycine, Furancarbonylglycine (Females Under Age 13), Furancarbonylglycine (Males Age 13 and Over), Furancarbonylglycine (Males Under Age 13), Glutaric, Glutaric (Females Under Age 13), Glutaric (Males Age 13 and Over), Glyceric, Glyceric (Males Age 13 and Over), Glycolic, Glycolic (Males Age 13 and Over), Hippuric, Hippuric (Females Under Age 13), Hippuric (Males Age 13 and Over), Homogentisic, Homogentisic (Males Age 13 and Over), Homovanillic (HVA), Homovanillic (HVA) (Males Age 13 and Over), HPHPA, HPHPA (Males Age 13 and Over), HVA / VMA Ratio, HVA / VMA Ratio (Males Age 13 and Over), HVA/ DOPAC Ratio, HVA/ DOPAC Ratio (Males Age 13 and Over), Kynurenic, Kynurenic (Males Age 13 and Over), Lactic, Lactic (Males Age 13 and Over), Lactic (Males Under Age 13), Malic, Malic (Males Age 13 and Over), Malic (Males Under Age 13), Malonic, Malonic (Males Age 13 and Over), Mandelic, Mandelic (Males Age 13 and Over), Methylcitric, Methylcitric (Males Age 13 and Over), Methylmalonic, Methylmalonic (Males Age 13 and Over), Methylsuccinic, Methylsuccinic (Males Age 13 and Over), N-Acetylaspartic, N-Acetylaspartic (Males Age 13 and Over), N-Acetylcysteine (NAC), N-Acetylcysteine (NAC) (Males Age 13 and Over), Orotic, Orotic (Females Under Age 13), Orotic (Males Age 13 and Over), Oxalic, Oxalic (Females Under Age 13), Oxalic (Males Age 13 and Over), Pantothenic (B5), Pantothenic (B5) (Males Age 13 and Over), Phenyllactic, Phenyllactic (Males Age 13 and Over), Phenylpyruvic, Phenylpyruvic (Males Age 13 and Over), Phosphoric, Phosphoric (Males Age 13 and Over), Pyridoxic (B6), Pyridoxic (B6) (Males Age 13 and Over), Pyroglutamic, Pyroglutamic (Males Age 13 and Over), Pyruvic, Pyruvic (Females Under Age 13), Pyruvic (Males Age 13 and Over), Quinolinic, Quinolinic (Males Age 13 and Over), Quinolinic / 5-HIAA Ratio, Sebacic, Sebacic (Males Age 13 and Over), Suberic, Suberic (Males Age 13 and Over), Succinic, Succinic (Females Under Age 13), Succinic (Males Age 13 and Over), Tartaric, Tartaric (Males Age 13 and Over), Thymine, Thymine (Males Age 13 and Over), Tricarballylic, Tricarballylic (Females Under Age 13), Tricarballylic (Males Age 13 and Over), Tricarballylic (Males Under Age 13), Uracil, Uracil (Males Age 13 and Over), Vanillylmandelic (VMA), Vanillylmandelic (VMA) (Males Age 13 and Over)
