In this study, all citizen of Nord-Trøndelag County, Norway, above 20 years of age are invited to participate in a population-based health study, the HUNT study. Blood samples are drawn from the participants and assessed for celiac disease by a serological assay. Celiac disease is a chronic inflammatory disease of the small intestine due to dietary gluten in wheat, barley and rye. The diagnosis will be verified through endoscopic assessment and biopsies from the small intestinal mucosa. The aims of the study are 1) to establish the population-based prevalence of celiac disease; 2) to assess the consequences of the disease from patient reported outcomes, symptoms, deficiencies, and co-morbidity; 3) to study possible risk factors and environmental triggering events; 4) to identify genetic predictors and gene-environmental interactions.

Inclusion Criteria:

• Participants of the forth round of the HUNT study

Exclusion Criteria:

• None