Hemoglobin A1c (HbA1c) with 24-hour fluid measurement by immunoassay

Why This Test Is Done

Doctors order HbA1c tests primarily to diagnose diabetes or monitor long-term blood sugar levels in people who already have diabetes. It’s especially useful because blood sugar levels fluctuate throughout the day, and a single reading doesn’t capture the full picture. This test helps prevent complications like nerve damage, kidney disease, or vision problems by identifying trends over time.

What to Expect Before the Test

No special preparation is needed for this test. You’ll typically have a small blood sample drawn from your arm, similar to a regular blood test. If your doctor specifically mentions a 24-hour fluid measurement, they may ask you to collect urine or other fluids over a set period, but this is rare for standard HbA1c testing.

How the Test Works

HbA1c measures the percentage of hemoglobin (the oxygen-carrying protein in red blood cells) that is attached to sugar (glucose). Over time, high blood sugar binds to hemoglobin, creating HbA1c. The test uses an immunoassay to detect this protein-sugar complex, providing a stable reflection of your average blood sugar levels.

What the Results Mean

Results are reported as a percentage (e.g., 5.7%, 6.4%, 7.5%). While exact ranges vary by lab, higher percentages generally indicate poorer blood sugar control. For example, a result below 5.7% is often considered normal, while 6.5% or higher may signal diabetes. Your doctor will interpret results in the context of your overall health and symptoms.