On standard blood glucose tests, the readings for people with untreated diabetes is higher than for people without the disease, according to the American Diabetes Association. However, people being treated for diabetes typically aim for results similar to those of nondiabetics.
People who do not have diabetes have fasting blood glucose scores of less than 100 milligrams per deciliter, states the ADA. This test is conducted after the patient has had no food or drink, except water, for eight hours. Diabetes is indicated with a reading of 126 milligrams per decimeter or more. Results in between suggest prediabetes.
The oral glucose tolerance test measures blood glucose before and two hours after consuming a specific sugary drink, the ADA reports. Normal results are less than 140 milligrams per deciliter, while 200 or higher indicates diabetes. Again, prediabetes falls between the two categories. A random glucose test is performed at any time. A score of 200 or more helps diagnose diabetes.
An A1C score reveals a patient's average blood glucose reading for two or three months, says the ADA. If the result is less than 5.7 percent, no diabetes is indicated. Diabetics have scores of 6.5 percent or more. Prediabetes ranges from 5.7 to 6.4 percent.