Coeliac Disease: A Common, Under-Diagnosed Autoimmune Condition Where Iron That Will Not Stay Up Is Often the First Clue, and the Only Rule That Matters Before Testing Is Keep Eating Gluten

Summary

Coeliac disease is a lifelong autoimmune reaction to gluten that affects roughly 1 in 100 people, yet only about a quarter are diagnosed, because it so often shows up not as obvious gut trouble but as iron deficiency that keeps coming back or will not respond to supplements, unexplained fatigue, mouth ulcers, or a blistering rash; the first-line screen is a simple blood test (tTG-IgA, requested with a total IgA), a positive result routes to a duodenal biopsy for confirmation in adults, and the single load-bearing rule is that the person **must still be eating gluten when tested** because going