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Histamine-to-Creatinine Ratio, Urine

Published: August 9, 2026Updated: August 16, 2026

A urine test that measures histamine relative to creatinine, which helps account for differences in urine concentration.

Quick summary

["This ratio can help evaluate increased histamine release, but results must be interpreted alongside symptoms and other tests."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
43577-6
Short code
Histamine/Creat Ur-Rto
Synonyms
Histamine/Creat Ur-Rto
Category
kidney
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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

What is this test?

This test measures histamine in urine and compares it with the amount of creatinine in the same sample. Creatinine is used as a reference because urine concentration can vary from person to person and throughout the day.

Why might I need this test?

It may be used to help evaluate unexplained flushing, hives, swelling, wheezing, diarrhea, or other symptoms that could be related to histamine release. It is sometimes considered when a clinician is evaluating a possible mast-cell disorder.

How is the test performed?

A urine sample is analyzed to determine the amounts of histamine and creatinine, and the laboratory calculates their ratio. The result may come from a single urine collection or a collection over a period specified by the laboratory.

How do I prepare for the test?

Follow the laboratory's collection instructions exactly, including the collection period and any storage requirements. Tell your clinician about medicines, supplements, and foods that may affect histamine, because these can influence interpretation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated urine histamine-to-creatinine ratio may indicate increased histamine release and can occur with mast-cell disorders or certain other conditions. A low result does not rule out a condition, and an abnormal result is not diagnostic by itself.

Short name

Urine Histamine/Creatinine Ratio

Frequently asked questions

Does this test diagnose mast-cell disorders?
No. The ratio may support further evaluation, but diagnosis usually requires a medical history, physical examination, and sometimes additional laboratory testing.
Can foods or medicines affect the result?
Yes. Some foods, alcohol, and certain medicines can alter histamine levels or affect how the result is interpreted. Do not stop prescribed medicines without medical advice.
Why is creatinine included in the test?
Creatinine helps account for how concentrated the urine is. Including it makes the histamine measurement more comparable between samples.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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