The test for A1C indicates how well you have controlled your diabetes over the last few months. Even though you may have some very high or very low blood glucose values, A1C will give you a picture of the average amount of glucose in your blood over that time period. The result can help you and your doctor know if the measures you are taking to control your diabetes are successful.

Depending on the type of diabetes that you have, how well your diabetes is controlled, and your doctor, your A1C may be measured 2 to 4 times each year. The American Diabetes Association recommends testing your A1C:

• 4 times each year if you have type 1 or type 2 diabetes and use insulin; or
  
• 2 times each year if you have type 2 diabetes and do not use insulin.

When someone is first diagnosed with diabetes or if control is not good, A1C may be ordered more frequently.

A healthy person without diabetes will have an A1C between 4% (0.04) and 6% (0.06). If you are diabetic, the closer your A1C is to 6% (0.06), the better your diabetes is in control. For every 1% (0.01) increase in A1C, blood glucose increases approximately 30 mg/dL (1.67 mmol/L) and the risk of complications increases.

PLEASE NOTE: Numerically reported test results are interpreted according to the test's reference range, which may vary by the patient's age, sex, as well as the instrumentation or kit used to perform the test. A specific result within the reference (normal) range – for any test – does not ensure health just as a result outside the reference range may not indicate disease. To learn more about reference ranges, please see the article, Reference Ranges and What They Mean. To learn the reference range for your test, consult your doctor or laboratorian. Lab Tests Online recommends you consult your physician to discuss your test results as a part of a complete medical examination.

If you have an abnormal type of hemoglobin, such as sickle cell hemoglobin, accurate results will depend on the method used to measure your A1C. If you have hemolysis or heavy bleeding, your test results may be falsely low. Finally, if you are iron deficient, this may raise your A1C measurement.