Diagnosis
The Diagnosis Journey, Step by Step
From the first suspicion to a confirmed result, here is what a careful, evidence-based path to diagnosis actually looks like.
A reliable celiac diagnosis is a sequence, not a single test. Skipping a step — or going gluten-free before testing — can produce false negatives that take years to untangle.
Phase one — recognition
The work begins with a pattern. A list of symptoms, a family history, a doctor who is willing to consider an autoimmune cause. Keep a symptom journal before your first appointment. Note timing, severity, and any food associations you've observed.
Phase two — serology
A blood test measures specific antibodies — most commonly tissue transglutaminase IgA (tTG-IgA) and total IgA. Elevated antibodies indicate a likely autoimmune response. You must be eating gluten regularly for at least six weeks before this test, or the result is meaningless.
Phase three — endoscopy
For most adults, a small-bowel biopsy is the confirmatory step. A gastroenterologist takes several tissue samples from the duodenum and a pathologist looks for the characteristic flattening of the villi, graded on the Marsh scale.
Phase four — the diagnosis conversation
A confirmed diagnosis comes with practical next steps: a referral to a dietitian experienced with celiac disease, baseline screening for common deficiencies (iron, B12, folate, vitamin D), a bone-density scan, and follow-up serology at six and twelve months.
Treatment is a strict, lifelong gluten-free diet. Done well, the intestine heals. Done partially, it does not.
