62 Tilley Drive
South Burlington, VT 05403-4407
We use many tests to help diagnose diabetes. To be diagnosed with diabetes you must meet one of the following criteria:
- Fasting Blood Glucose (sugar): a fasting blood glucose of greater than or equal to 126 mg/dl. Fasting means after not having anything to eat or drink except water for at least 8 hours before the test.
- A1C (Hemoglobin A1C): An A1C level higher than 6.5 is positive for diabetes. This test shows the amount of glucose that sticks to the red blood cell, which is related to the amount of glucose in the blood. This test measures your average blood glucose for the past 2 to 3 months and is not a fasting lab test.
- Random (also called Casual) Plasma Glucose Test: This test is a blood check at any time of the day when you have diabetes symptoms. If the blood glucose is greater than or equal to 200 mg/dl you are diagnosed with diabetes.
- Oral Glucose Tolerance Test (also called the OGTT): This is a two-hour test that checks your blood glucose levels before and 2 hours after you drink a beverage containing glucose. An OGTT is most commonly done to check for diabetes that occurs with pregnancy (gestational diabetes). Diabetes is diagnosed at 2 hour blood glucose of greater than or equal to 200 mg/dl.
We often repeat testing on different days to confirm a diabetes diagnosis.
Sometimes testing shows that blood glucose levels are higher than normal but not high enough to diagnose you with diabetes. This means you have a condition known as prediabetes and are at risk of developing diabetes in the future.
Test results indicating prediabetes are:
- A1C: 5.7% - 6.4%
- Fasting blood glucose: 100 - 125 mg/dl
- An OGTT 2 hour blood glucose: 140 mg/dl - 199 mg/dl
Learn more about Diabetes treatments or call 802-847-4576.