Ketosis-prone diabetes is a condition characterized by high levels of ketones in the blood. This type of diabetes is also known as atypical diabetes or ketosis-prone type 2 diabetes. There are several synonyms for the term ketosis-prone diabetes including atypical diabetes mellitus, fulminant diabetes, ketosis-prone type 2 diabetes mellitus, and type 1.5 diabetes. These terms are used interchangeably to describe the same condition where individuals exhibit characteristics of both type 1 and type 2 diabetes. Ketosis-prone diabetes presents a unique challenge for healthcare providers as treatment approaches must consider both the insulin resistance found in type 2 diabetes and the autoimmune component of type 1 diabetes.