Blood test
Coeliac Disease Blood Test
A coeliac blood test looks for antibodies produced when someone with coeliac disease eats gluten. It is the first step in diagnosing the condition.
Quick answer
Coeliac Disease Blood Test: what it is and what the results mean
This blood test measures antibodies (most commonly tissue transglutaminase, or tTG) that are raised in coeliac disease, an immune reaction to gluten. It is the usual first test when coeliac disease is suspected.
- Why it is done: It is used to investigate symptoms such as tummy pain, bloating, diarrhoea, tiredness or unexplained anaemia, and to screen relatives of people with coeliac disease or those with related conditions.
- Understanding results: A positive antibody result makes coeliac disease likely and usually leads to a gut biopsy (gastroscopy) to confirm it.
What it is
This blood test measures antibodies (most commonly tissue transglutaminase, or tTG) that are raised in coeliac disease, an immune reaction to gluten. It is the usual first test when coeliac disease is suspected.
Why it is done
It is used to investigate symptoms such as tummy pain, bloating, diarrhoea, tiredness or unexplained anaemia, and to screen relatives of people with coeliac disease or those with related conditions.
What to expect
It is a standard blood test from the arm. Importantly, you need to be eating gluten regularly for a period beforehand, otherwise the test can be falsely negative.
Understanding the results
A positive antibody result makes coeliac disease likely and usually leads to a gut biopsy (gastroscopy) to confirm it. A negative result while eating gluten makes it unlikely, though further assessment is sometimes needed.
Good to know
Risks and limitations
The blood test is very safe. Its accuracy depends on eating gluten beforehand, and a positive result usually needs confirming with a biopsy rather than being relied on alone.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Coeliac Disease Blood Test: frequently asked questions
Do I need to eat gluten before a coeliac test?
Yes. You should be eating gluten regularly for several weeks beforehand, otherwise the antibodies may not be raised and the test can be falsely negative. Do not cut out gluten before testing.
Does a positive result confirm coeliac disease?
A positive antibody test makes coeliac disease likely but is usually confirmed with a gut biopsy taken during a gastroscopy. Your clinician will explain the next steps.
Related tests
Other blood test investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Association for Laboratory Medicine / relevant professional body
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