Biological diagnosis of diabetes mellitus

Diabetes mellitus is a common disease whose complications are severe. For decades, the diagnosis of diabetes and prediabetes was using only fasting glucose or glucose two hours during an oral glucose tolerance test. Recently, it is possible to use HbA_1c. Each of these tests has advantages and limitations that must be well known by clinicians for better care for patients. So they could use one, two or three of this tests to reach to a proper diagnosis. The aim of this article is about the strong and weak points of these tests.