glucose · HbA1c · A1C
Hemoglobin A1c
HbA1c reflects average blood glucose over ~3 months. It is a cornerstone metabolic-health and longevity marker.
This page is general wellness education, not medical advice. Your own lab’s reference range and your clinician’s interpretation always take precedence.
Typical reference range
| Group | General range |
|---|---|
| Adults | Normal < 5.7%; 5.7–6.4% prediabetes; ≥6.5% diabetes range |
Optimal-band note: Lower-normal A1c is often a healthspan target, but very low values can reflect other conditions — context matters.
Units: %. Ranges vary by lab and assay — read yours against the range printed on your own report.
What high Hemoglobin A1c can mean
- Insulin resistance / diabetes
- High refined-carb diet
- Inactivity
- Certain anemias (falsely high)
What low Hemoglobin A1c can mean
- Hypoglycemia
- Hemolytic anemia / blood loss (falsely low)
- Recent transfusion