what is hgb a1c in blood test

The Hemoglobin A1C (HbA1c) test, also known as the 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 your diabetes is being managed.

How Does It Work?

• 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 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.