what is a1c in blood work

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, as well as to monitor how well your diabetes is being managed.

How Does It Work?

• 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 enters your bloodstream, it attaches to hemoglobin.
• The higher your blood sugar levels, the more glucose attaches to hemoglobin.

A1C Ranges:

A1C Level Diagnosis

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

Why Is It Important?

• It provides a long-term view of blood sugar control, unlike daily glucose tests that only show a snapshot.
• It helps healthcare providers adjust treatment plans for diabetes management.

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