The prevalence of diabetes has been consistently rising, and it has become a substantial global public health issue. It is a metabolic condition that disrupts carbohydrate management, marked by the body’s inability to produce or properly respond to insulin, leading to challenges in regulating normal blood sugar levels. All forms of diabetes may be managed with medication and lifestyle changes; however, most are chronic conditions. Increased appetite, thirst, and frequent urination result from this elevated blood sugar. Numerous issues can arise from diabetes if left untreated. Nonketotic hyperosmolar coma and diabetic ketoacidosis are examples of acute complications. Long-term significances include heart disease, neuro-problems, foot ulcers, liver damage, and vision loss. The two main causes of diabetes are insufficient insulin production by the pancreas and improper insulin cellular response. Many forms of diabetes are covered in this chapter, along with the current treatments and strategies for managing people with diabetes before and after treatment. The guidelines for diagnosing diabetes mellitus provided by the American Diabetes Association are also addressed.