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Emily Eye Care, LLC
Lily Yeh, OD
Aaron Lewis, OD

Home » Newsletters » What is a Diabetes A1c Test?

What is a Diabetes A1c Test?


During the course of Diabetes care, most patients have a special blood test done every 3 months.  It is called the hemoglobin A1c test.  The major benefit of the A1c test is that it provides a measure of how your blood glucose levels have averaged over the past 2-3 months, and so gives more of a "big picture" if your overall blood sugar control.  The daily blood glucose checks that you do yourself give you a measure of your blood glucose level at that moment, but daily blood glucose levels can fluctuate quite a bit.  The A1c test is extremely important for monitoring how well your Diabetes is controlled.  
The A1c test measures the amount of sugar (glucose) that is stuck to the hemoglobin molecules of our red blood cells, which typically live about 2-3 months before being replaced by new red blood cells.  By comparing how much sugar is stuck (bound) to new and old red blood cells, the A1c result gives an average of a person's blood glucose levels over the last 2-3 month period.  Studies show the A1c number predicts the likelihood of suffering diabetes complications, especially eye and kidney damage. This means the A1c result is literally a quality of life number.  

The good news is this is a very simple test to understand.  It is reported as a small number, and should be below 7.  For most people with diabetes, the A1c should be between 6 and 7- this indicates good, consistent control.  If your A1c number is lower than 6, that is even better.  But any reading below 7 is generally considered acceptable. 

Many times, health care providers are too busy and/or patients simply don't ask about their blood work.  The purpose of the handout is to encourage you to take a more active role in your diabetes care.  One very important factor in your diabetes care is for you to always ask your doctor or nurse to inform you of your A1c number.  They will be glad to share this important information with you.

knowing your A1c number will enable you to know how your overall diabetic control is.  Be sure to ask any number of your diabetes care team any questions that you may have about your care.

A final note: The retina within the eye is the only place in the body where blood vessels can be observed and evaluated.  Since Diabetes primarily affects the blood vessels, it is very important to have a dilated eye examination every year.  This is eve more important if your A1c readings tend to be higher than 7.


American Diabetes Association
American Diabetes Association Journals
Centers for Disease Control and Prevention - Diabetes Public Health Resource