Type 1 Diabetes mellitus is a chronic condition in which the pancreas does not produce or produce only a little insulin. It usually occurs during the period of adolescence. It is an autoimmune disorder as the immune system destroys the insulin-producing cells called Beta cells present in the pancreas. This leads to little or no production of insulin. The person suffering from Type 1 Diabetes mellitus develops symptoms like increased thirst, frequent urination, increased hunger, weakness, tiredness, unexplained weight loss, and blurring of vision. Genetics is believed to play a major role in causing type 1 Diabetes mellitus. If Type 1 Diabetes mellitus is left untreated it leads to complications like coronary heart disease, neuropathy, nephropathy, skin and mouth conditions, and retinopathy.