Gluten-related disorders have become an epidemiologically significant phenomenon, with an estimated prevalence of about 5% worldwide. The current classification of gluten-related disorders is based mainly on their pathophysiology, and the following categories can be distinguished: Immune-mediated disorders, which include celiac disease, allergic reactions, such as wheat allerg, and non-celiac gluten sensitivity, a condition characterized by both gastrointestinal and extraintestinal symptoms, which has recently gained popularity. Diagnostic errors in gluten-associated diseases are still a pressing clinical problem. Based on the literature, we propose a practical methodological approach to guide clinicians on how to recognize them and avoid errors. The first part of the review presents literature data on the history, causal factors in the development of gluten-related diseases, and autoimmune gluten intolerance celiac disease.