Diabetes Mellitus is a long-term metabolic condition marked by high blood sugar levels resulting from issues with insulin secretion, insulin function, or a combination of both. It is broadly classified into Type 1 (autoimmune destruction of pancreatic beta cells) and Type 2 (insulin resistance and relative insulin deficiency). Chronic complications encompass cardiovascular disease, neuropathy, nephropathy, and retinopathy. Management involves lifestyle changes, blood glucose monitoring, and pharmacologic therapy including insulin and oral agents.