Understanding the Results of Your A1C Test

Medically Reviewed By William C. Lloyd III, MD, FACS
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Testing your own blood sugar (glucose) helps you manage your diabetes on a daily basis. Still, you will want to work with your doctor to find out how well your diabetes treatment plan is controlling your blood sugar over time. That’s where an A1C test can help—it provides information about your average levels of blood sugar over the previous 2 to 3 months. Here’s a look at how the A1C test works and what your doctor is looking for through this important number.

What is the A1C test?

The A1C test is the primary test used for diabetes management. The higher your A1C level, the poorer your glucose control and the greater your risk of diabetes complications.

The glucose in your bloodstream is a sugar that binds to hemoglobin—a protein in red blood cells that carries oxygen from the lungs to all the cells of the body. The more glucose in your blood, the more linking (glycating) there is of glucose and hemoglobin. Sugar stays attached to hemoglobin for about 90 days, which is the lifetime of a cell.

That’s where the A1C test comes in. It’s a blood test that measures the amount of sugar bound to hemoglobin and doesn’t show sudden or recent changes in blood sugar. Your doctor will look at your A1C test results as more of an average when it comes to assessing how well your diabetes treatment plan is working overall, not just what your self-testing results have been over time.

Why should you have an A1C test?

Knowing your A1C level can show how likely it is that you will develop complications of diabetes. Complications from diabetes can include cardiovascular disease and stroke, diabetic retinopathy, cataracts, blindness, kidney damage and kidney failure, peripheral neuropathy, and problems during pregnancy.

The A1C test doesn’t require that you fast, and blood for the test can be drawn anytime of the day. Knowing your A1C testing level confirms the daily blood sugar readings you take at home. Results from the test tells your doctor if your treatment plan is working, and shows how making healthy choices in eating, activity, stress reduction and taking medications as prescribed affects your blood sugar over time.

What do test results mean?

Your doctor will discuss test results with you and help you figure out what your target A1C should be. That target will depend on your age, overall health, the type of diabetes you have, and other factors.

A1C results are reported as a percentage. 

  • The target for most people with diabetes is an A1C lower than 7%.
  • For people who do not have diabetes, an A1C below 5.7% is normal.

Your goal will be to reach the lowest possible A1C without your blood sugar getting so low that you have symptoms.

How often should I have an A1C test?

The American Diabetes Association recommends A1C testing twice a year for people with diabetes who are meeting treatment goals and whose blood glucose levels are stable. Keeping your A1C close to normal means your diabetes is well controlled, which lessens the chance you will develop complications of diabetes that may impact your heart, blood vessels, eyes, kidneys, and nerves.

If your A1C is too high, however, your doctor will likely suggest adjustments to your medication, meals, or activity levels. You will then take another A1C test to check whether these changes help control your blood sugar levels.

Working closely with your doctor to monitor your A1C level is key component of your overall diabetes care. By taking an active role in understanding your A1C results, you can find an effective diabetes treatment plan that fits into your lifestyle and keeps your long-term symptoms under control.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Aug 6
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. The A1C Test and Diabetes. National Institute of Diabetes and Digestive and Kidney Diseases. http://www.niddk.nih.gov/health-information/health-topics/diagnostic-tests/a1c-test-diabetes/Pages/i...
  2. A1C and eAG. American Diabetes Association. http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-glucose-control/a1c/