A1C is a blood test for type 2 diabetes and prediabetes. It measures your average blood glucose, or blood sugar, level over the past 3 months. Doctors may use the A1C alone or in combination with other diabetes tests to make a diagnosis. They also use the A1C to see how well you are managing your diabetes. This test is different from the blood sugar checks that people with diabetes do every day.
Your A1C test result is given in percentages. The higher the percentage, the higher your blood sugar levels have been:
- A normal A1C level is below 5.7 percent
- Prediabetes is between 5.7 to 6.4 percent. Having prediabetes is a risk factor for getting type 2 diabetes. People with prediabetes may need retests every year.
- Type 2 diabetes is above 6.5 percent
- If you have diabetes, you should have the A1C test at least twice a year. The A1C goal for many people with diabetes is below 7. It may be different for you. Ask what your goal should be. If your A1C result is too high, you may need to change your diabetes care plan.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
- A1C and eAG (American Diabetes Association) Also in Spanish
- A1C Test (American Association for Clinical Chemistry)
- A1C Test and Diabetes (National Institute of Diabetes and Digestive and Kidney Diseases)
- Blood Test: Hemoglobin A1C (Nemours Foundation) Also in Spanish
- For People of African, Mediterranean, or Southeast Asian Heritage: Important Information about Diabetes Blood Tests (National Institute of Diabetes and Digestive and Kidney Diseases)
- Know Your Blood Sugar Numbers: Use Them to Manage Your Diabetes (National Diabetes Education Program) Also in Spanish
- ClinicalTrials.gov: Hemoglobin A, Glycosylated (National Institutes of Health)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
- Article: HbA1c Identifies Subjects With Prediabetes and Subclinical Left Ventricular Diastolic...
- Article: Impact of common genetic determinants of Hemoglobin A1c on type...
- Article: Prolonged, Uninterrupted Sedentary Behavior and Glycemic Biomarkers Among US Hispanic/Latino...
- A1C -- see more articles