GETTING TESTED
By Centers for Disease Control and Prevention
Type 1 Diabetes, Type 2 Diabetes, and Prediabetes
Your doctor will have you take one or more of the following blood tests to confirm the diagnosis:
A1C Test
This measures your average blood sugar level over the past 2 or 3 months. An A1C below 5.7% is normal, between 5.7 and 6.4% indicates you have prediabetes, and 6.5% or higher indicates you have diabetes.
Fasting Blood Sugar Test
This measures your blood sugar after an overnight fast (not eating). A fasting blood sugar level of 99 mg/dL or lower is normal, 100 to 125 mg/dL indicates you have prediabetes, and 126 mg/dL or higher indicates you have diabetes.
Glucose Tolerance Test
This measures your blood sugar before and after you drink a liquid that contains glucose. You’ll fast (not eat) overnight before the test and have your blood drawn to determine your fasting blood sugar level. Then you’ll drink the liquid and have your blood sugar level checked 1 hour, 2 hours, and possibly 3 hours afterward. At 2 hours, a blood sugar level of 140 mg/dL or lower is considered normal, 140 to 199 mg/dL indicates you have prediabetes, and 200 mg/dL or higher indicates you have diabetes.
Random Blood Sugar Test
This measures your blood sugar at the time you’re tested. You can take this test at any time and don’t need to fast (not eat) first. A blood sugar level of 200 mg/dL or higher indicates you have diabetes.