Diagnostic Tests  for Type 2 Diabetes

1. Glycated hemoglobin (A1C) test- The A1C test measures your average blood sugar for the past two to three months. The advantages of being diagnosed this way are that you don't have to fast or drink anything. Diabetes is diagnosed at an A1C of greater than or equal to 6.5%

Normalless than 5.7%
Diabetes6.5% or higher

This blood test, which doesn't require fasting, indicates your average blood sugar level for the past two to three months. It measures the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells. The higher your blood sugar levels, the more hemoglobin you'll have with sugar attached


If the A1C test results aren't consistent, the test isn't available, or you have certain conditions that can make the A1C test inaccurate  such as if you are pregnant or have an uncommon form of hemoglobin (known as a hemoglobin variant)  your doctor may use the following tests to diagnose diabetes:

1.Fasting Plasma Glucose- This test checks your fasting blood sugar levels. Fasting means after not having anything to eat or drink (except water) for at least 8 hours before the test. This test is usually done first thing in the morning, before breakfast. Diabetes is diagnosed at fasting blood sugar of greater than or equal to 126 mg/dl

Fasting Plasma Glucose (FPG)
Normalless than 100 mg/dl
Diabetes126 mg/dl or higher

2. Random blood sugar test.-This test is a blood check at any time of the day when you have severe diabetes symptoms. Diabetes is diagnosed at blood sugar of greater than or equal to 200 mg/dl.

3. Oral glucose tolerance test (OGTT) - The OGTT is a two-hour test that checks your blood sugar levels before and two hours after you drink a special sweet drink. It tells the doctor how your body processes sugar. Diabetes is diagnosed at 2 hour blood sugar of greater than or equal to 200 mg/dl

Normal less than 140 mg/dl
Diabetes 200 mg/dl or higher

References-  1. Diagnosis | ADA. (2019). Diabetes.org. https://www.diabetes.org/a1c/diagnosis