Coeliac disease is a relatively common chronic autoimmune disorder that occurs in genetically predisposed individuals following the ingestion of gluten, a protein found in wheat, barley, and rye. The condition primarily affects the small intestine, where an immune-mediated response leads to villous atrophy, impaired nutrient absorption, and a spectrum of gastrointestinal and extraintestinal symptoms. Diagnosis typically involves serological testing for specific antibodies and histological examination of small bowel biopsy. The management is strict, lifelong adherence to a gluten-free diet, which generally results in symptom resolution and mucosal recovery. It is vital to diagnose coeliac disease early to prevent long-term complications, including an increased risk of certain malignancies. Although dietary exclusion of gluten remains the only effective treatment, ongoing research is focused on better understanding the underlying mechanisms of the disease and exploring novel therapeutic approaches that could complement or replace the gluten-free diet in the future.