what is a hemoglobin a1c test

The Hemoglobin A1C (HbA1c) test is a blood test that measures your average blood sugar (glucose) levels over the past 2 to 3 months. It is commonly used to:

• Diagnose prediabetes and diabetes.
• Monitor how well your diabetes treatment plan is working.

How It Works

• Glucose in your blood attaches to hemoglobin, a protein in red blood cells.
• The A1C test measures the percentage of hemoglobin coated with glucose.
• Since red blood cells regenerate every 3 months, the test reflects your average blood sugar over that period.

A1C Results

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

Why It’s Important

• It provides a long-term view of blood sugar control, unlike daily glucose checks.
• It helps healthcare providers adjust treatment plans to prevent complications.

For more details, visit CDC's A1C Test Guide.