HbA1c (Hemoglobin A1c) measures average blood glucose levels over the previous 2-3 months. It is the most reliable test for diabetes diagnosis and long-term glucose management.
Why it matters
Unlike a single blood sugar reading which fluctuates with meals, HbA1c reflects long-term glucose exposure. It cannot be falsely lowered by short-term dieting before the test.
How to interpret your result
An HbA1c of 7% corresponds to an estimated average glucose of 154 mg/dL. Each 1% increase represents approximately a 29 mg/dL increase in average glucose.
When to get tested
At least annually if you have diabetes. Every 3-6 months if your diabetes is not well controlled. Every 3 years after age 45, or earlier if you have risk factors.