What is the A1c test?

Daily blood glucose monitoring captures your blood sugar levels at one moment in time. But the A1c test measures your blood glucose average over the past two to three months, making it an invaluable tool for your doctor to see how your diabetes treatment plan is working.


Here are some common questions and answers about the A1c test:

How does the A1c test work?

Within your bloodstream, a protein called hemoglobin is in charge of carrying oxygen throughout the body. This hemoglobin travels within red blood cells. If there is excess sugar in the bloodstream, the glucose will attach to the hemoglobin (glycated). The A1c test measures how much of the hemoglobin has been glycated.


Why is the test used?

Often doctors use the A1c test to first diagnose people with type 1 or type 2 diabetes. As part of your diabetes treatment plan, your doctor may administer the A1c test regularly to check how your treatment plan is working and to see whether adjustments are needed to better manage your diabetes care.


How often should I have the A1c test?

The frequency of your A1c tests will be determined by your doctor. The ADA (American Diabetes Association) says that people with diabetes should check your A1c twice a year at a minimum, or more frequently when necessary. The ADA also points out that the A1c test is not meant to replace daily blood glucose monitoring.


How is the test taken?

The A1c test is a simple blood test. You do not have to be fasting or follow any special dietary restrictions beforehand. After your doctor collects your blood sample, it will be sent to a laboratory to determine your result.


What kind of result should I expect?

A normal A1c level is below 5.7%. For people with diabetes, test results are typically 6.5% or above. For those experiencing prediabetes, the A1c results range is between 5.7 and 6.4%.

*These figures are based on information from the U.S. Department of Health and Human Services.


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