Among all developing countries, India accounts for almost 43 million which correspond to one sixth of the total diabetics. Approximately every fifth or sixth patient is getting admitted in ICU because of diabetes mellitus (DM). In order to achieve a strict glycemic control, intensive efforts along with dedicated efforts of supporting staff, frequent glucose monitoring and implementation of intensive insulin regimens are required. Overenthusiastic administration of insulin and oral hypoglycemic drug are the main causes of hypoglycemia condition. The topic on clinical features explain about various complications and indications associated with DM, hyperglycemia and glycemic control. The intensive insulin treatment (IIT) is a most globally used treatment for hyperglycemia and this is used in the intensive care units of India. IIT shows good metabolic control in HDL and LDL and also show significant low level of CRP. Glucose-insulin-potassium (GIK) regimen along with insulin provides better cardio-protection. Capillary glucose measurement is mainly used in the routine glucose tests. Complications, transition therapy and prognosis and prevention are also dealt in this chapter.