Hello paticus, welcome to the forum. Most doctors follow the guidelines from the American Diabetes Association for diagnosis. Normal fasting is accepted as under 100; "prediabetic" would be 100 to 125 and diabetes is 126 and higher. However, most doctors will have you test a few times and if they see an upward trend, they might order a glucose tolerance test and an A1c, which is a simple blood test that gives an average of your blood sugar over the past 3 months. Some medications like prednisone and other steroids can cause high blood sugar while you're taking it. There are other meds that cause high blood sugar too. I hope this helps.
forum moderator - diabetes
diabetes controlled so far by exercise and a low/no carb diet