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A 50-year-old member asked:

Can a fasting blood glucose test alone tell you that you have diabetes?

2 doctor answers8 doctors weighed in
Dr. Susan Wingo
Endocrinology 33 years experience
Needs confirmation: A single fasting blood sugar over 125 needs confirmatory tests to diagnose diabetes. this can be a second fasting blood sugar over 125, or a Hemoglobin A1c test over 6.5%. However any sugar over 300, or any sugar over 200 associated with vision change, excessive thirst or urination, or weight loss while eating more than usual is diagnostic for diabetes without a need for confirmatory testing.
Dr. Thomas Knecht
A Verified Doctoranswered
A US doctor answeredLearn more
Yes, absolutely: Hi. Yes, a fasting serum glucose is easily diagnostic of diabetes. There are 4 means of diagnosing diabetes: fasting serum glucose, random serum glucose, 2-hr glucose tolerance test, and A1c. Fasting glucose is an easy test, and if positive, should be repeated for confirmation. Eat healthily and exercise regularly. Keep your diabetes, blood pressure, and lipids well controlled. DON'T SMOKE!

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Last updated Nov 16, 2014

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