what is the test for a1c

The A1C test, also known as the hemoglobin A1C or HbA1c test, is a blood test that measures your average blood sugar 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 the A1C Test 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.
• Red blood cells regenerate every 3 months, which is why the A1C test reflects your average blood sugar levels over that period.

A1C Test Ranges:

A1C Level Diagnosis

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

Why Is It Important?

• The A1C test provides a long-term view of blood sugar control, unlike daily blood sugar checks, which only show a snapshot.
• It helps healthcare providers adjust treatment plans for diabetes management.

How Is the Test Done?

• A blood sample is taken from your arm or finger.
• No fasting is required before the test.

For more details, consult your healthcare provider or visit CDC's A1C Test Page.