Type 1 diabetes mellitus is a chronic irreversible condition resulting from a lack of insulin caused by autoimmune destruction of pancreatic beta cells; underlying triggers for this are not yet identified. Early recognition of signs and symptoms is essential as insulin insufficiency results in hyperglycaemia and, if undiagnosed, the life-threatening complication of diabetic ketoacidosis (DKA) occurs. There is short-term impact on and long-term implications to health, due to associated complications.

Type 2 diabetes occurs because of insufficient insulin production or resistance by the body’s cells to insulin. Treatment options are determined by the severity and progression of the condition. Management options include diet and physical activity, oral medication and insulin. Incidence within children and adolescents is increasing; rationale for this includes changes in lifestyle and reduction in exercise and obesity.

Other types of diabetes can occur as a result of underlying medical conditions or treatment, and they can also be attributable to genetic factors.