Home > Patients & Visitors > Health Library > What Is A1c?
A1c is a test that shows the average level
of blood sugar over the past 2 to 3 months. People who have
diabetes need to have this test done regularly to see
whether their blood sugar levels have been staying within a target
range. This test is also used to diagnose diabetes.
A1c test results show your average blood sugar
level over time. The result is reported as a percentage. Your goal is to keep
your hemoglobin A1c level as close to your target level as possible. You and your doctor will work together to set your safe target level.
The result of
your A1c test can also be used to estimate your average blood sugar
level. This is called your estimated average glucose, or eAG. Your eAG and A1c
show the same thing in two different ways. They both help you know about your
average blood sugar over the past 2 to 3 months.
The table below
shows A1c with estimated average glucose.
Estimated average glucose (mg/dL)
American Diabetes Association (2016). Standards of medical care in diabetes–2016. Diabetes Care, 39(Suppl 1): S1–S112.
ByHealthwise StaffPrimary Medical ReviewerE. Gregory Thompson, MD - Internal MedicineKathleen Romito, MD - Family MedicineSpecialist Medical ReviewerRhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
Current as ofFebruary 19, 2016
Current as of:
February 19, 2016
E. Gregory Thompson, MD - Internal Medicine & Kathleen Romito, MD - Family Medicine & Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
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