Have symptoms of diabetes (increased thirst,
increased urination, and unexplained weight loss) and a blood sugar level equal
to or greater than 200
milligrams per deciliter (mg/dL). The blood sugar test
is done at any time, without regard for when you last ate (random plasma
glucose test or random blood sugar test).
Have a fasting blood
sugar level that is equal to or greater than 126 mg/dL. A fasting blood sugar
test (fasting plasma glucose) is done after not eating or drinking anything but
water for 8 hours.
Have a 2-hour oral glucose tolerance test (OGTT) result that is equal to or greater than 200 mg/dL. An OGTT is most commonly done to check for diabetes that occurs with pregnancy (gestational diabetes).
Your doctor may repeat the test to confirm the diagnosis of diabetes.
If the results of your
fasting blood sugar test are between 100 mg/dL and 125 mg/dL, your OGTT result is between 140 to 199 mg/dL (2 hours after the beginning of the test), or your hemoglobin A1c is 5.7% to 6.4%, you have
prediabetes. This means that your blood sugar is above normal but not high enough to be diabetes. Discuss with your doctor how
often you need to be tested.footnote 1
American Diabetes Association (2012). Diagnosis and classification of diabetes mellitus. Diabetes Care, 35(Suppl 1): S64-S71.