The fasting glucose level for people with diabetes is 126 milligrams per deciliter or above, according to the National Diabetes Information Clearinghouse. Prediabetic individuals have results between 100 and 125 milligrams per deciliter. A person with a normal blood sugar level scores 99 or less.
The fasting plasma glucose test, or FPT, is commonly used to diagnose diabetes, because it is convenient and relatively inexpensive when compared to other analyses, NDIC states. Patients must fast for eight hours prior to the FPT. Tests done in the morning are most reliable. Physicians typically order diabetic screening tests for people who display specific risk factors. These include being overweight or obese, having a family history of diabetes, being physically inactive or having high blood pressure.