Understanding HbA1c: What the 3-Month Blood Sugar Average Really Means
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A deep dive into HbA1c — what the test measures, why 7% is the target, and how it connects to nerve and vessel damage that puts feet at risk.
HbA1c is the single most important number on your diabetes report. Here's what it actually measures and why your care team keeps coming back to it.
What HbA1c measures
HbA1c (also called A1C or glycated hemoglobin) is the percentage of your red blood cells that have sugar attached to them. Because red blood cells live about three months, this test gives a rolling average of your blood sugar over that window — not a snapshot like a fingerstick.
A single high reading after a big meal doesn't move your A1C much. But sugar that stays elevated day after day, week after week, shows up here.
Why 7% is the target for most adults
| HbA1c | Estimated average glucose |
|---|---|
| 6% | ~126 mg/dL |
| 7% | ~154 mg/dL |
| 8% | ~183 mg/dL |
| 9% | ~212 mg/dL |
| 10% | ~240 mg/dL |
At or below 7%, the risk of long-term complications — nerve damage, vessel damage, kidney damage, eye damage — drops significantly. Your individual target may be a little higher or lower depending on age and other conditions; ask your clinician what's right for you.
How HbA1c connects to your feet
Every percentage point above target represents months of elevated sugar quietly damaging small nerves and blood vessels. In the feet, that shows up as:
- Neuropathy — loss of protective sensation, so you don't feel the pebble in your shoe
- Peripheral arterial disease — reduced blood flow, so wounds struggle to heal
These two together are how a small injury becomes a diabetic foot ulcer.
What moves the number
- Consistent medication use
- A plate that's half vegetables, with limited added sugar
- Regular movement, cleared with your clinician
- Home glucose monitoring so you catch trends early
- Sleep and stress management, which both affect glucose
HbA1c changes slowly. Expect to see meaningful movement over three to six months of steady habits — not three to six days.
Learn more about diabetic foot care and how the healing dashboard helps your care team monitor progress.