Type 1 diabetes mellitus

**Definition:** Diabetes mellitus type 1 (type 1 diabetes, T1DM, formerly insulin dependent or juvenile diabetes) is a form of diabetes mellitus that results from destruction of insulin-producing beta cells, mostly by autoimmune mechanisms. The subsequent lack of insulin leads to increased blood and urine glucose.

**Exclusions:** - Type 2 diabetes mellitus - Diabetes mellitus, other specified type - Diabetes mellitus in pregnancy