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What causes type 1 diabetes?

The underlying cause of type 1 diabetes is an inappropriate reaction of a defence system created by a complex combined effect of genetics and external factors.

Type 1 diabetes is an autoimmune disease. The underlying cause of the autoimmune disease is genetics and an inflammation of the insulin-producing cells of the pancreas as a combined result of viruses, gut microbes and, potentially, some nutritional factors. In the case of type 1 diabetes, the reaction targets the insulin-producing beta cells of the islets of the pancreas. As a result of the inflammation, the cells are damaged and their ability to produce insulin for the body is reduced and will eventually, at some point, come to an end. The autoimmune inflammation of the beta cells of the pancreas may have been going on for several weeks or even years before blood sugar reaches diabetic levels.

For now, the exact causes of type 1 diabetes or methods to prevent it are not known. There is a wide range of ongoing research into the risk factors and preventive methods of type 1 diabetes. A lot of the research is especially aimed at viral infections and nutritional factors.

A person with type 1 diabetes also has a higher-than-average predisposition to other autoimmune diseases. They include autoimmune thyroiditis, coeliac disease and vitiligo.

Type 1 diabetes was once known as juvenile onset diabetes or juvenile diabetes. These terms are no longer used because type 1 diabetes is not age-dependent and person may get it at any age. However, the majority still develop the disease before the age of 40.

Updated 30.9.2023