Celiac disease

For a lay person:

Coeliac disease is an immune reaction to gluten, a protein in wheat, barley and rye. Eating gluten damages the lining of the small intestine, which can cause digestive symptoms, tiredness and poor absorption of nutrients.

For a trained medical person:

An immune-mediated enteropathy triggered by gluten in genetically susceptible people (HLA-DQ2/DQ8). Diagnosis is by serology (tissue transglutaminase IgA) and duodenal biopsy while still eating gluten. Treatment is a strict lifelong gluten-free diet.

In Chinese medicine:

Flaws and Sionneau's textbook differentiates this condition into these patterns: Liver-spleen disharmony with internal brewing of damp heat; Qi and yin deficiency with internal brewing of damp heat. Treatment follows the pattern a patient presents with, not the Western diagnosis alone.

When to get help: Don't start a gluten-free diet before testing; it can make the diagnosis impossible to confirm.