What HbA1c Means, and How Often It Should Be Checked

HbA1c (glycated hemoglobin) is a blood test that reflects your average blood glucose over roughly the past two to three months — unlike a fingerstick or lab glucose reading, which only shows a single moment in time. The result is reported as a percentage: it reflects the proportion of hemoglobin in your blood that has glucose attached to it. As average blood glucose runs higher, that percentage rises too. As a general guide, an HbA1c below 5.7% is considered in the normal range, 5.7–6.4% falls in the prediabetes range, and 6.5% or above is consistent with a diabetes diagnosis. For people already diagnosed with diabetes, individualized targets are set by your care team based on your overall health, other conditions, and treatment plan — a single target doesn't fit everyone. How often it's checked depends on your situation. General guidance suggests testing roughly every three months if you're not yet at your target or have recently changed treatment, and roughly every six months once you're stable at goal — but your care team will set a schedule that fits your specific case. One thing worth knowing: HbA1c can be affected by conditions that change red blood cell turnover, including some forms of anemia — one reason diabetes and anemia are sometimes evaluated together. If you use a continuous glucose monitor, that gives a complementary, day-to-day picture rather than replacing periodic HbA1c testing — the two are typically used alongside each other, not instead of one another.