Glycated hemoglobin or A1C is a blood test that shows the average level of blood sugar over the previous 2 to 3 months. A1C is reported as a percent.

eAG is reported in mg/dL (mmol/L). This is the same measurement used in home blood sugar meters.

eAG is calculated directly from your A1C results. Because it uses the same units as home meters, eAG makes it easier for people to understand their A1C values relative to their home blood sugar readings. Health care providers now use eAG to talk with their patients about A1C results.

Knowing your eAg can help you:

• Understand the value of tracking your blood glucose levels over time
• Relate to your self-test blood glucose readings
• Better manage diabetes by seeing how your lifestyle and medicine choices affect blood sugar;

You and your provider can see how well your diabetes care plan is working by looking at your eAG readings.

The normal value for eAG is between 70 mg/dl and 126 mg/dl (A1C: 4% to 6%). A person with diabetes should aim for an eAG less than 154 mg/dl (A1C < 7%) to lower the risk for diabetes complications.

The results of an eAG test may not match your average of day-to-day blood sugar tests you have been taking at home on your glucose meter. This is because you are likely to check your sugar levels before meals or when your blood sugar levels are low. But it does not show your blood sugar at other times of the day. So, the average of your results on your meter may be different than your eAG.

Your doctor should never tell you what your blood sugar values are based on the eAG because the range of average blood glucose for any individual person is very broad for each A1c level. The value is only an estimate.

There are many medical conditions and medicines that change the relationship between A1c and eAG. Do not use eAG to evaluate your diabetes control if you:

• Have conditions such as kidney disease, sickle cell disease, anemia, or thalassemia
• Are taking certain medicines, such as dapsone, erythropoietin, or iron

eAG

American Diabetes Association. 6. Glycemic targets: Standards of Medical Care in Diabetes-2021. Diabetes Care. 2021;44(Suppl 1):S73-S84. PMID: 33298417 pubmed.ncbi.nlm.nih.gov/33298417/.

American Diabetes Association website. Diabetes overview. A1C and eAG. www.diabetes.org/diabetes/a1c-test-meaning/a1c-and-eag. Accessed July 6, 2021.

American Diabetes Association website. Toolkit no.15. All about blood glucose. professional.diabetes.org/sites/professional.diabetes.org/files/media/All_about_Blood_Glucose.pdf. Accessed July 6, 2021.

Updated by: Brent Wisse, MD, Board Certified in Metabolism/Endocrinology, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.