What is a Hemoglobin A1c Test?

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What is a Hemoglobin A1c Test?:


A hemoglobin A1c test, sometimes referred to as just A1c, is a test used to measure your average blood sugar (also called glucose) over the past two to three months. It is an important benchmark for people with diabetes because it gives you a way to gauge the levels of glucose in your bloodstream over a relatively long period of time.

Daily blood testing gives you a reliable measure of glucose in your blood at that moment.

But, unless you use a continuous glucose monitor, there is no accurate way to know how much your blood sugar fluctuates between checks. Even if you check your blood several times a day, you may not have an accurate picture of your long-term blood sugar. The A1c test is your best way to learn what has been going on.

How is the A1c test performed?

An A1c test is usually done in your doctor’s office or at a lab. Many doctors now have technology where they can obtain a small blood sample, about the amount you would use on your own glucose meter, and obtain instant results. It is simple, fast and accurate. If the sample needs to be sent to the lab, you can usually obtain the results within a couple of days.

Recommendations for A1c testing

The most recent Clinical Practice Guidelines from the American Diabetes Association, revised in 2011, recommend that the A1c test be performed:

  • at least two times a year for those who are consistently meeting their diabetes management goals and have stable glucose control.
  • quarterly for those who are not consistently meeting their diabetes management goals and/or have significant fluctuations in their blood sugar. Your doctor may also recommend quarterly testing if he or she makes changes to your treatment plan.

If you want to stay on top of your long-term blood sugar pattern, your best coverage is to schedule an A1c test on a quarterly basis.

This way you will always have an informed idea of how your diabetes management efforts are working.


American Diabetes Association. American Diabetes Association’s New Clinical Practice Recommendations Promote A1C as Diagnostic Test for Diabetes.

Hypoglycemia. American Diabetes Association. Accessed August 18, 2008. Executive Summary: Standards of Medical Care in Diabetes—2011.Diabetes Care, 2010; vol. 30, 51-510.

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