Criteria for Diagnosing Diabetes
- 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).
- Have a hemoglobin A1c that is 6.5% or higher.
The diagnosis of diabetes needs to be confirmed by repeating the same blood sugar test or doing a different test on another day.
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.1
|Primary Medical Reviewer||E. Gregory Thompson, MD - Internal Medicine|
|Specialist Medical Reviewer||David C.W. Lau, MD, PhD, FRCPC - Endocrinology|
|Last Revised||July 16, 2013|
Last Revised: July 16, 2013
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