what does a1c mean in a blood test

The A1C test, also known as the hemoglobin A1C or HbA1c test, is a blood test that measures your average blood sugar levels over the past 2 to 3 months. It is commonly used to diagnose prediabetes and diabetes, as well as to monitor how well you are managing your condition if you already have diabetes.

How It Works:

• The test measures the percentage of your red blood cells that have sugar-coated hemoglobin.
• Hemoglobin is a protein in red blood cells that carries oxygen. When glucose (sugar) enters your bloodstream, it attaches to hemoglobin.
• The higher your blood sugar levels, the more glucose attaches to hemoglobin.
• Since red blood cells regenerate every 3 months, the A1C test reflects your average blood sugar levels over that period.

A1C Results:

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

Why It’s Important:

• The A1C test provides a broader picture of blood sugar control compared to daily glucose checks, which only show a snapshot of your blood sugar at a single point in time.
• It helps healthcare providers assess your risk for diabetes-related complications and adjust your treatment plan if necessary.

For more detailed information, you can refer to the CDC's guide on A1C testing.