what is hb1ac blood test

The HbA1c test, also known as the hemoglobin A1c test or A1c 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, as well as to monitor how well you are managing your diabetes over time.

How does it work?

• Glucose in your bloodstream 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 Results and What They Mean:

A1c Level (%) Diagnosis

Below 5.7 Normal
5.7 - 6.4 Prediabetes
6.5 or higher Diabetes

Why is it important?

• It provides a long-term view of blood sugar control.
• It helps healthcare providers adjust treatment plans for diabetes.

For more details, consult your healthcare provider or visit CDC's A1c Test Page.