 Type II diabetes mellitus, T2DM, has become increasingly common in recent years, with no clear explanation as to why. This review looks at the epidemiological data, modern theories of the disease's development, and the role of endothelial dysfunction in the progression of T2DM. It also discusses the cost of healthcare systems due to the disease's complications. This article was authored by M. U. Sharifova, S. H. S. Sagdiva, and S. D. Yusufi.