This review discusses the relationship between diabetes mellitus and oxidative stress. Diabetes is a metabolic disorder characterized by high blood glucose levels and insulin deficiency or resistance. There are two main types of diabetes: Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent). Type 1 diabetes results from autoimmune destruction of pancreatic beta cells, while Type 2 diabetes is caused by insulin secretion defects and resistance. Oxidative stress occurs when there is an imbalance between reactive oxygen species (ROS) and antioxidants. ROS are highly reactive molecules that can damage cells, leading to various complications in diabetes, such as stroke, neuropathy, retinopathy, and nephropathy. Free radicals, including ROS and reactive nitrogen species (RNS), are produced in the body and can cause oxidative damage to lipids, proteins, and DNA. Antioxidants help neutralize free radicals and prevent oxidative stress. Biomarkers of oxidative stress in diabetes include proteins, lipids, vitamins, glutathione, catalase, and superoxide dismutase. These biomarkers are used to assess the extent of oxidative damage in diabetic patients. Oxidative stress plays a significant role in the pathogenesis of diabetes and its complications. It contributes to the development of vascular complications, including atherosclerosis and endothelial dysfunction. The review highlights the importance of antioxidants in the prevention and treatment of diabetes and its complications. It also emphasizes the need for further research to better understand the mechanisms of oxidative stress in diabetes and to develop effective therapeutic strategies.This review discusses the relationship between diabetes mellitus and oxidative stress. Diabetes is a metabolic disorder characterized by high blood glucose levels and insulin deficiency or resistance. There are two main types of diabetes: Type 1 (insulin-dependent) and Type 2 (non-insulin-dependent). Type 1 diabetes results from autoimmune destruction of pancreatic beta cells, while Type 2 diabetes is caused by insulin secretion defects and resistance. Oxidative stress occurs when there is an imbalance between reactive oxygen species (ROS) and antioxidants. ROS are highly reactive molecules that can damage cells, leading to various complications in diabetes, such as stroke, neuropathy, retinopathy, and nephropathy. Free radicals, including ROS and reactive nitrogen species (RNS), are produced in the body and can cause oxidative damage to lipids, proteins, and DNA. Antioxidants help neutralize free radicals and prevent oxidative stress. Biomarkers of oxidative stress in diabetes include proteins, lipids, vitamins, glutathione, catalase, and superoxide dismutase. These biomarkers are used to assess the extent of oxidative damage in diabetic patients. Oxidative stress plays a significant role in the pathogenesis of diabetes and its complications. It contributes to the development of vascular complications, including atherosclerosis and endothelial dysfunction. The review highlights the importance of antioxidants in the prevention and treatment of diabetes and its complications. It also emphasizes the need for further research to better understand the mechanisms of oxidative stress in diabetes and to develop effective therapeutic strategies.