Although the exact cause of celiac disease is not known, having certain genes increases your risk. You are more likely to have these genes and may get celiac disease if you have a first-degree relative (mother, father, brother, sister, son, or daughter) with the condition. Environmental factors, such as viral or bacterial infections, may trigger changes in the small intestine in people with these genes; then, eating foods that contain gluten can trigger an abnormal immune system response. Eventually, digestion and absorption problems may result.

Research continues on how genetic, environmental, and immune factors interact and affect a person's symptoms, at what age they begin, and whether long-term health problems develop.