Is my HbA1c (Hemoglobin A1C) normal?
Free blood test checker · Standard + longevity-optimal ranges
What is a normal HbA1c level?
HbA1c measures your average blood sugar over the past 2-3 months. It's the gold standard for diabetes screening and monitoring. A normal HbA1c is below 5.7%, prediabetes is 5.7-6.4%, and diabetes is 6.5% or higher. Longevity researchers target below 5.4%.
| Range | Values |
|---|---|
| Standard Reference | 4–5.7 % |
| Optimal | 4–5.4 % |
| Longevity Optimal | < 5.4% |
| High Risk | > 6.5 % |
What causes abnormal HbA1c levels?
Elevated HbA1c is caused by chronically high blood sugar from insulin resistance, excess refined carbohydrate intake, sedentary lifestyle, obesity (especially visceral fat), chronic stress, poor sleep quality, and genetic predisposition to type 2 diabetes. Certain medications like corticosteroids can also raise blood sugar.
When should you see a doctor?
See your doctor if your HbA1c is 5.7% or above (prediabetes range), if you have symptoms like increased thirst, frequent urination, or unexplained fatigue, or if you have a family history of diabetes. If already diagnosed with diabetes, work with your doctor to keep HbA1c below your target (typically under 7%).
Where to get a HbA1c test
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Related biomarkers
These biomarkers are often tested alongside HbA1c for a more complete picture.
Frequently asked questions
What is a normal HbA1c level?
Can HbA1c be lowered naturally?
How often should I check HbA1c?
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Sources: Reference ranges based on AHA/ACC, ADA, and AACE clinical guidelines. Biological variation data from Ricos/Westgard database. Longevity-optimal ranges reflect targets used by preventive and functional medicine practitioners.
Last reviewed: April 2026. This tool provides general health information and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider about your specific results.