Celiac blood test
Checks whether gluten is triggering an immune reaction that damages the gut - the first step in diagnosing celiac disease.
TypeBlood test
HowStandard blood draw.
How oftenOnce if symptoms or risk; repeat if symptoms change.
BeforeKeep eating gluten daily for at least 6 weeks before.
WhoPeople with bloating, diarrhea, iron deficiency, or a close relative with celiac.
Why timing and gluten matter
Celiac disease is an immune reaction to gluten. The test looks for the antibodies your body makes when you eat it. Cut gluten first and the antibodies fade - so the test can come back falsely normal.
Keep eating gluten
“Should I go gluten-free first?”
No. Test first, while eating gluten daily.
Test before changing diet
Beyond the gut
“I don’t have gut symptoms.”
Celiac can show up as low iron, fatigue, bone loss or rashes.
Often hidden
Positive result
“What happens next?”
Usually a gut biopsy (endoscopy) to confirm, before going gluten-free for life.
Confirm, then treat
Is it right for you?
Worth considering if…
- You have ongoing bloating, diarrhea or abdominal pain.
- You have unexplained iron deficiency or low bone density.
- A parent, sibling or child has celiac disease.
- You have type 1 diabetes or autoimmune thyroid disease.
A better option if…
- You’re already gluten-free - talk to your provider about a supervised gluten challenge or genetic testing (HLA-DQ2/DQ8) first.
- You suspect a wheat allergy - that’s tested with IgE testing.
How it’s measured
tTG-IgA with total IgA
The standard first test - total IgA makes sure the result is valid.
Other antibodies (EMA, DGP)
Used in special situations.
Genetic test (HLA-DQ2/DQ8)
A negative result makes celiac very unlikely.
The full picture
What is it?
A blood test for antibodies produced in celiac disease.
What type of test is it?
A blood biomarker.
What does it measure?
tTG-IgA and total IgA levels.
Why might someone consider it?
Celiac is common, often missed, and damages the gut if untreated.
Who is it most relevant for?
People with symptoms, deficiencies or family history.
How is it performed?
A routine blood draw while eating gluten.
How often might it be considered?
Once; repeated if symptoms change.
What can the result help you understand?
Whether celiac disease is likely.
What are its limitations?
False negatives if you’ve cut gluten or have low IgA.
What should it be viewed with?
Iron, B12, folate, vitamin D and bone density.
Where to get it
Through your provider
The simplest route - often covered when there’s a clear reason.
Lab services
e.g. Quest Diagnostics, Labcorp.
Direct-to-consumer panels
e.g. Function Health, InsideTracker.
Names are examples only, not endorsements. Your provider can often order the same test - and help interpret it.
Connected to
Questions to ask your provider
- Should I keep eating gluten before this test?
- Do I need an endoscopy if it’s positive?
Ziva Health
One test is a snapshot. Ziva shows the whole story.
Ziva brings your lab results, wearables and daily readings together - and Isabella tells you what’s changing and what to ask your provider next.
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Is your provider not on Ziva yet? Send them a link in under a minute - once they join, they’ll see your Celiac blood test result alongside your other trends and get alerts directly.
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Being listed doesn’t mean everyone needs this test. Educational only — not medical advice. Results should be interpreted with a qualified clinician. ← Back to Know What to Test