Diabetes mellitus is generally defined by disturbances in glucose metabolism, resulting in increased blood glucose concentration.
Among other forms, type I and type II diabetes mellitus are differentiated.
Diabetes mellitus type I is an autoimmune disease (overreaction of the immune system against the body). Usually at a young age, the insulin-producing cells of the pancreas are destroyed. There is a lack of insulin, the hormone that regulates the carbohydrate metabolism and is responsible for the uptake of blood glucose into the cells.
In diabetes mellitus type II, there is usually enough insulin present. However, due to so called "insulin resistance", sugar uptake is inhibited despite normal insulin levels, leading to elvated blood glucose concentration. Obesity is one of the main causes of diabetes mellitus type II, .