Diabetes Mellitus: An Updated Review of Disease Mechanisms, Risk Factors, Complications, and Integrated Management

Diabetes mellitus refers to a group of metabolic disorders in which circulating glucose rises because insulin production is inadequate, insulin action is impaired, or both abnormalities are present. Major categories include type 1, type 2 and gestational diabetes, alongside less common forms associated with inherited defects, pancreatic disorders, endocrine disease or medicines. Persistent hyperglycaemia can gradually injure blood vessels and organs, particularly the heart, kidneys, retina and peripheral nerves. This review discusses diabetes classification, underlying mechanisms, risk assessment, diagnostic approaches, complications and current management. It also considers person-centred nutrition and activity plans, glucose monitoring, appropriate medicine use and the contribution of pharmacists. Comprehensive care should aim for safe glucose control while addressing cardiovascular and renal risk, preventing complications and maintaining day-to-day wellbeing.