Which range describes normal, prediabetes, and diabetes for A1C?

• A. <6.5% normal; 6.5-7.5% prediabetes; >7% diabetes
• B. <4.5% normal; 4.5-5.5% prediabetes; >6.0% diabetes
• C. <5.7% normal; 5.7-6.4% prediabetes; >6.5% diabetes
• D. <6.0% normal; 6.0-6.9% prediabetes; >7.0% diabetes

Answer: (C)

A1C ranges are used to classify long-term blood glucose control. The A1C test reflects the average blood glucose over about the past three months by measuring the percentage of hemoglobin that has glucose attached.

The best ranges match established guidelines: normal is below 5.7%, prediabetes is 5.7% to 6.4%, and diabetes is 6.5% or higher. An A1C of 5.7% signals higher-than-normal glucose and typically prompts lifestyle or risk-reduction efforts; 6.5% or higher indicates diabetes and usually leads to more formal diagnostic confirmation and treatment planning. These thresholds help guide screening, prevention, and management.

Other ranges don’t align with these standard cutoffs, so they don’t correctly separate normal, prediabetes, and diabetes.