The risk of hypoglycemia increase among patient with diabetes mellitus and/or on insulin as compare to general population. Hypoglycemia is defined as blood glucose <70mg/dl or <4 mmol/L. Iatrogenic or medicine induce is most common cause of hypoglycemia. Hypoglycemia is associated with various fatal complications. Among type 1 diabetes, it is relate with 4-10% of deaths. The mortality rate correlates with severe hypoglycemia in both type 1 and type 2 diabetes is 3.4 folds higher versus those with milder event. It is necessary to give education regarding hypoglycemia prevention, drug dose adjustment, avoid skipping meal and treat immediately as “15-15 rule”. Use injection glucagon or IV glucose in case of severe hypoglycemia.