Diabetes mellitus type 1 (also known as type 1 diabetes, or T1DM; formerly insulin-dependent diabetes or juvenile diabetes) is a form of diabetes mellitus that results from the autoimmune destruction of the insulin-producing beta cells in the pancreas. The subsequent lack of insulin leads to increased blood and urine glucose. The classical symptoms are polyuria (frequent urination), polydipsia (increased thirst), polyphagia (increased hunger) and weight loss. The cause of diabetes mellitus type 1 is unknown. Type 1 diabetes can be distinguished from type 2 by autoantibody testing. The C-peptide assay, which measures endogenous insulin production, can also be used. Administration of insulin is essential for survival. Insulin therapy must be continued indefinitely and does not usually impair normal daily activities. People are usually trained to manage their diabetes independently; however, for some this can be challenging. Untreated, diabetes can cause many complications. Acute complications include diabetic ketoacidosis and nonketotic hyperosmolar coma. Serious long-term complications include heart disease, stroke, kidney failure, foot ulcers and damage to the eyes. Furthermore, complications may arise from low blood sugar caused by excessive treatment. Diabetes mellitus type 1 accounts for 5% of cases of diabetes. Globally, the number of people with DM type 1 is unknown, although it is estimated that about 80,000 children develop the disease each year. Within the United States the number of affected persons is estimated at one to three million. The development of new cases vary by country and region; the lowest rates appears to be in Japan and China with approximately 1 person per 100,000 per year; the highest rates are found in Scandinavia where it is closer to 35 new cases per 100,000 per year. The United States and northern Europe fall somewhere in between with 8-17 new cases per 100,000 per year.