any of various abnormal conditions characterized by the secretion and excretion of excessive amounts of urine, esp diabetes mellitus diabetes mellitus
There are two main types, both with genetic predisposition. Type 1 is due to deficiency of the hormone insulin, and occurs when the body's immune system attacks the insulin-producing beta cells in the pancreas (an autoimmune disease). Type 2 (85% of diabetes) is characterized by defective insulin action (‘insulin resistance’), exacerbated by lifestyle factors and associated with obesity – Professor Leonard C Harrison
[via Latin from Greek diabētēs, from diabainein to go through, from dia- + bainein to go; so called because of the thirst and excessive urination associated with diabetes]