Prediabetes - Exams and Tests

Who should be tested for prediabetes?

If you haven't yet been diagnosed with prediabetes, you may want to talk to your doctor about testing. The American Diabetes Association recommends testing adults for prediabetes, which may lead to type 2 diabetes, if you:1

If the tests are normal, the American Diabetes Association recommends repeat testing at least every 3 years.

A child who weighs too much may develop serious health problems, including type 2 diabetes. For more information about testing children for diabetes, see the topic Type 2 Diabetes in Children.

What tests will you have for prediabetes?

Your doctor will do a medical history, a physical exam, and blood glucose testing to find out if you have prediabetes and are at risk for getting type 2 diabetes.

Blood tests used to identify prediabetes in adults include:

  • Fasting blood glucose test. This test is usually done after you fast overnight for 8 hours.
  • Hemoglobin A1c. This test estimates your blood sugar over the past 2 to 3 months.
  • Oral glucose tolerance test (OGTT). For an OGTT, your blood sugar is measured after fasting and then again 2 hours after you drink a special glucose liquid. This test is not done as often as the fasting glucose test, which is more convenient.

You have prediabetes if:

  • The results of your A1c test are 5.7% to 6.4%. For all of these tests, lower numbers are best.
  • The results of your fasting blood glucose test are 100 to 125 milligrams per deciliter (mg/dL).
  • The results of your OGTT are 140 to 199 mg/dL (2 hours after the beginning of the test).

Phrases such as "a touch of diabetes," "borderline diabetes," and "your sugar is a little high" are unclear. If you hear these phrases, ask your doctor if your blood sugar level is in the prediabetes or diabetes range.

Tests for other health problems

If you are diagnosed with prediabetes, your doctor may also want to:

WebMD Medical Reference from Healthwise
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