what is a1c on blood test

The A1C test, also known as the hemoglobin A1C or 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 blood sugar control in people with diabetes

How It Works

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

A1C Ranges

A1C Level Diagnosis

Below 5.7% Normal
5.7%–6.4% Prediabetes
6.5% or higher Diabetes

For people with diabetes, the goal is typically to keep their A1C below 7%, though this may vary based on individual health conditions.