Diabetes mellitus is a class of metabolic diseases all of which have in common high levels of sugar in the blood (glucose) that result from problems with insulin secretion, its action, or both. Usually, blood sugar is controlled by a hormone secreted by the pancreas called insulin. When there is an increase in blood sugar, the pancreas releases insulin to normalize blood sugar. There are mainly two types of diabetes: type 1 and type 2.
Both types are chronic diseases that affect the way blood sugar levels or the regulation of glucose in the body. Glucose is like the fuel that nourishes the cells of the body, but to get into the cells it needs a key which is insulin.
Type 1: People with diabetes of this type do not produce insulin.