If your body is healthier and your red blood cells live longer, your HbA1c blood sugar test might show higher levels — not because your blood sugar is high, but because the sugar has more time to...

If your red blood cells live longer, they soak up more sugar over time, which can make your HbA1c blood test go up — even if your average blood sugar hasn't actually changed.

If your red blood cells live longer than usual, your A1C test might show high blood sugar even if your actual sugar levels are normal.

Your HbA1c number isn't just about your average blood sugar — it also depends on how long your red blood cells live. The longer they stick around, the more sugar builds up on them, which can raise your HbA1c even if your blood sugar is stable.

HbA1c might show high blood sugar even in people who actually have normal levels, because some people's red blood cells live longer than usual.

Sometimes, blood sugar tests that don’t use HbA1c might give a better picture of how well someone’s diabetes is managed—especially if things like blood disorders or other health issues make the standard HbA1c test less reliable.