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

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

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

Quick summary

["Helps assess histamine-related conditions like allergies, mast cell disorders, or histamine intolerance."]

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

Key facts at a glance

LOINC
108648-7
Short code
E histolyt DNA Msmt Stl
Synonyms
E histolyt DNA Msmt Stl
Category
chemistry
Sample
stool
Container
Clean container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
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 persistent itching, hives, flushing, or digestive issues that don’t improve with usual allergy treatments. It could also be used to evaluate conditions linked to abnormal histamine levels, such as mastocytosis or certain food intolerances.

How the Test Works

Blood: A sample of your blood is taken and analyzed for histamine concentration. Urine: A 24-hour urine collection is used to measure histamine excretion over time. The test detects histamine levels in your body’s response to allergens or other triggers.

What to Expect Before the Test

For blood tests: No special preparation is needed, but avoid heavy meals before drawing blood. For urine tests: Collect all urine for 24 hours, starting after your first morning void. Drink plenty of water to maintain urine flow.

Common Conditions Monitored

This test helps diagnose or monitor conditions like severe allergies, mast cell activation syndrome, or histamine intolerance, which can cause symptoms like skin rashes, digestive upset, or respiratory issues.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Histamine Profile

Frequently asked questions

What does a high or low histamine level mean?
High levels may indicate overactive mast cells, allergic reactions, or histamine intolerance. Low levels might suggest a deficiency or a condition affecting histamine metabolism, though this is less common. Results help guide treatment plans for managing symptoms.
How long will I need to wait for results?
Results typically take 1–3 business days, depending on lab processing times. Your doctor will discuss the findings with you during your follow-up visit.
Can I take antihistamines before the test?
Yes, but avoid taking antihistamines for at least 24–48 hours before the test to get an accurate reading, as they can interfere with histamine measurement.
  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