Your biosensor shows your recent average glucose in your interstitial fluid, while A1c is a laboratory blood test that measures the amount of glucose stuck to your red blood cells. An A1c generally reflects typical glucose levels over the past ~3 months. Because they measure different things and reflect different time periods, they will not always line up. A1c can also be affected by factors unrelated to glucose, like red blood cell lifespan or iron levels, so even with accurate CGM data and A1c tests, it is normal for the two numbers to differ.
Even though your CGM average may not match your A1c exactly, it is still one of the best tools for improving A1c because it helps you understand how your daily habits affect your glucose in real time. By using the CGM to identify patterns like meals, stress, or sleep that raise glucose, you can make changes that impact your glucose less over time, which ultimately contributes to a lower A1c. Lingo provides actionable meal-to-meal and day‑to‑day insights, while A1c confirms long‑term progress.