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.

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.

HbA1c might not give a true picture of blood sugar control in people with diabetes because things like how often blood sugar swings, different ethnic backgrounds, and other health problems can affect the results.

Doctors usually rely on the HbA1c blood test to see how well someone with diabetes has managed their blood sugar over time — but some experts are starting to question if it’s always accurate for everyone.

There's a new math formula that fixes HbA1c blood sugar readings for people with type 2 diabetes when their red blood cells don't live as long as usual — this could give a more accurate picture of their blood sugar control.

If someone with type 2 diabetes has red blood cells that don’t live as long, their A1c test might be giving a lower number than their real blood sugar levels — meaning the test could be misleading for them.