Hemoglobin A1c (HbA1c) with Immunoassay Method (Serum)

Why Is This Test Done?

Your healthcare provider may order this test if you have diabetes, prediabetes, or if you’re at risk for diabetes. It helps track how well your blood sugar is controlled over time, especially if you take medications like insulin or oral diabetes drugs.

A small blood sample is taken from your arm, usually by a healthcare professional. The blood is processed into serum and sent to a lab for analysis using an immunoassay method to detect hemoglobin bound to sugar.

Results are reported as a percentage (e.g., 5.5%–6.4% is considered prediabetes; 6.5% or higher may indicate diabetes). While reference ranges vary by lab, higher percentages generally mean poorer blood sugar control.

Factors like recent blood loss, severe illness, or certain medications (e.g., some blood thinners) can temporarily affect HbA1c levels. Chronic conditions like kidney disease or anemia may also influence results.

For people with diabetes, HbA1c testing is often recommended every 3–6 months to monitor progress with treatment. Your provider will tailor frequency based on your health goals and current status.

HbA1c is a key indicator of long-term blood sugar management. Consistently high levels increase the risk of diabetes complications, such as nerve damage, kidney disease, or heart problems. It’s also useful for adjusting treatment plans to improve outcomes.

No special preparation is needed, but inform your provider if you’re taking blood-thinning medications or have recently had a blood donation. Avoid fasting unless instructed, as it may affect glucose levels temporarily.