Criteria for Diagnosing Diabetes

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Topic Overview

To be diagnosed with diabetes , you must meet one of the following criteria: footnote 1

  • 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. footnote 1

References

Citations

  1. American Diabetes Association (2012). Diagnosis and classification of diabetes mellitus. Diabetes Care, 35(Suppl 1): S64–S71.

Credits

ByHealthwise Staff
Primary Medical Reviewer E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer David C.W. Lau, MD, PhD, FRCPC - Endocrinology

Current as ofNovember 14, 2014