What blood glucose levels are considered normal?
When fasting, the glucose level in the blood of people without diabetes is less than 100 milligrams per decilitre or, in other words, less than 5.6 millimoles per litre. After eating, the blood glucose level usually rises somewhat, but not above 140 milligrams per decilitre.
Only when the blood glucose level exceeds 126 milligrams per decilitre when fasting or 200 milligrams after eating is it called diabetes mellitus.
Values between 100 and 125 mg/dl in the fasting state can already indicate a preliminary stage of type 2 diabetes. The final diagnosis can be clarified with a so-called glucose tolerance test (OGTT).