The document discusses diabetes mellitus (DM), including its types and management. DM is characterized by high blood glucose levels due to defects in insulin production or action. The main types are type 1 DM resulting from autoimmune destruction of insulin-producing cells, type 2 DM associated with insulin resistance, and gestational DM occurring during pregnancy. Lifestyle changes including diet and exercise, as well as medication, are used to manage blood glucose levels and prevent complications of DM such as damage to organs and tissues.