Explore the fundamentals of diabetes mellitus in this comprehensive 56-minute lecture, the first of a two-part series. Delve into the definition, causes, and various types of diabetes, including Type I, Type II, gestational, LADA, MODY, and secondary diabetes mellitus. Examine the differences between diabetes insipidus and mellitus, and understand the underlying mechanisms of the disease. Learn about the complications associated with diabetes, focusing on both macrovascular and microvascular issues such as coronary artery disease, cerebrovascular disease, peripheral artery disease, diabetic nephropathy, and diabetic retinopathy. Gain valuable insights into the global burden of diabetes and its impact on patients' lives through this informative medical lecture.