Is 108 A High Fasting Glucose Level?

Medically Reviewed


Asked by Carol

I haven't been diagnosed with diabetes, but I have had lots of blood work over the years and my fasting glucose is always between 100 and 108 mg/dL. I thought anything under 110 was fine, but I just wanted to make sure?


The ADA says that a fasting blood glucose level should be under 126 mg/dL.

The fasting plasma glucose (FPG) test has been the standard test for diabetes. It is a simple blood test taken after 8 hours of fasting. FPG levels indicate:

  • Normal: 100 mg/dL (or 5.5 mmol/L) or below
  • Prediabetes: between 100 mg/dL (5.6 mmol/L) and 125 mg/dL (6.9 mmol/L)
  • Diabetes: 126 mg/dL (7.0 mmol/L) or higher

The FPG test is not always reliable, so a repeat test is recommended if the initial test suggests the presence of diabetes, or if the test is normal in people who have symptoms or risk factors for diabetes. If you believe you may have prediabetes or diabetes, you should talk to your health care providers about diagnosis and treatment.