what is the highest a1c

The A1C test measures your average blood sugar levels over the past 2-3 months. The results are reported as a percentage. Here are the general ranges:

• Normal: Below 5.7%
• Prediabetes: 5.7% to 6.4%
• Diabetes: 6.5% or above

There isn't a defined "highest" A1C level, but extremely high A1C levels (e.g., above 10%) indicate very poor blood sugar control and a high risk of diabetes complications. If your A1C is very high, it's crucial to work with your healthcare provider to manage your blood sugar levels effectively.