Review symptoms and risk factors
Check family history of celiac disease
Order celiac blood tests while eating gluten
Test tissue transglutaminase IgA
Test total serum IgA
Test deamidated gliadin peptide antibodies if needed
Test endomysial antibodies if needed
Confirm positive blood tests with upper endoscopy and small bowel biopsy
Look for villous atrophy and increased intraepithelial lymphocytes on biopsy
Consider HLA-DQ2 and HLA-DQ8 testing if diagnosis is unclear
Do not start a gluten-free diet before testing is complete
Repeat testing or specialist evaluation if results are inconclusive