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Histamine concentration in serum/plasma (24-hour urine)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of histamine, a chemical released by your body during allergic reactions, over a 24-hour period in either your blood serum/plasma or urine.

Quick summary

["Helps assess histamine-related conditions like allergies or histamine intolerance."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
82207-2
Short code
E histolyt DNA Stl Ql NAA+n-prb
Synonyms
E histolyt DNA Stl Ql NAA+n-prb
Category
chemistry
Sample
stool
Container
Clean container
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
non-probe-amp-tar
CPT
84484
SNOMED
302774002
Specimen volume
5 g
Stability
Refrigerated: 24h, Frozen: 7d
TAT
4–24 hours
Order
routine

Why This Test Might Be Ordered

Your doctor may recommend this test if you have symptoms like itching, hives, or digestive issues that suggest an allergic reaction or histamine intolerance. It can also help diagnose conditions like mastocytosis or other histamine-related disorders.

What to Expect Before the Test

For serum/plasma: You’ll have a small needle inserted into your arm to draw blood. For urine: You’ll collect all urine for 24 hours in a special container. Avoid certain medications (like antihistamines) that may affect results.

How the Test Works

Blood or urine samples are analyzed to measure histamine levels. The test checks for elevated histamine, which may indicate overproduction or improper breakdown in your body.

Possible Results and Next Steps

High histamine levels may point to allergies, mastocytosis, or histamine intolerance. Low levels could suggest other conditions like histamine degranulation syndrome. Your doctor will discuss results and next steps, such as dietary changes or further testing.

Reference range

Adult: 10-40 U/LN/A

Specimen: stool

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Frequently asked questions

What does elevated histamine mean?
Elevated histamine levels may indicate conditions like allergic reactions, mastocytosis, or histamine intolerance. These can cause symptoms such as itching, flushing, digestive issues, or headaches. Your doctor may recommend dietary adjustments or other treatments to manage symptoms.
What if my results are normal?
Normal results don’t rule out histamine-related issues entirely. Some people may have mild fluctuations or conditions that aren’t detected by this single test. Your doctor may suggest additional testing or lifestyle changes to help identify the cause of your symptoms.
How can I prepare for this test?
For blood tests: Fast for 8–12 hours before drawing blood. For urine tests: Collect all urine in a container for 24 hours, starting after waking up. Avoid over-the-counter antihistamines or supplements that may affect results, as approved by your doctor.
  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 17, 2026. · Read our editorial policy