what does hemoglobin a1c measure

The Hemoglobin A1C (HbA1c) test measures your average blood sugar (glucose) levels over the past 2 to 3 months. Here's how it works:

• Hemoglobin is a protein in red blood cells that carries oxygen.
• When glucose enters your bloodstream, it attaches to hemoglobin, forming glycated hemoglobin.
• The A1C test calculates the percentage of your red blood cells that have glucose-coated hemoglobin.

Key Points:

• Normal A1C: Below 5.7%
• Prediabetes: 5.7% to 6.4%
• Diabetes: 6.5% or higher

The test is used to diagnose prediabetes and diabetes, as well as to monitor how well your diabetes is being managed over time.