Understanding Your A1C
A1C is one of the most commonly ordered lab values in medicine, and one of the most misunderstood. Even patients who know their number misunderstand what it's actually measuring, what can throw it off, or what it doesn't capture at all.
So here's a plain-language version...because understanding your labs is part of understanding your health.
What A1C actually measures
A1C measures the percentage of your hemoglobin that has glucose attached to it, which gives an estimate of your average blood sugar over the past two to three months. It's useful because a single fasting glucose reading only captures one moment in time. A1C gives a longer view.
The standard ranges most labs report: below 5.7% is considered normal, 5.7–6.4% is pre-diabetes, and 6.5% or above is diabetes.
But here's where it gets more interesting. "Normal" and "optimal" aren't always the same thing. From an integrative medicine standpoint, we look for A1C closer to the 4.8–5.4% range as a marker of genuinely healthy glucose metabolism, not just an absence of disease. An A1C of 5.6% clears the conventional bar, but it's worth a closer look at the full metabolic picture, especially if it's been trending upward over time.
What A1C doesn't tell you
A1C is an average, which means it can look perfectly normal while masking real problems. Someone who spikes high after every meal and then crashes low can have the same A1C as someone with stable blood sugar all day. The number looks the same but the metabolic picture is completely different.
A1C also doesn't measure insulin resistance, the condition where your body produces insulin but stops responding to it efficiently. Insulin resistance is often present for years before A1C budges, and it's one of the strongest predictors of future metabolic problems, weight changes, and cardiovascular risk.
What we look at instead – or in addition to
When a patient's metabolic health is on our radar, we're also looking at fasting insulin, triglycerides, HDL, glucose trends over time, and how you actually feel...energy after meals, cravings, afternoon crashes, changes in how your body holds weight. Those signals often tell us more than a single A1C number.
A 5.4% that's been creeping up from 5.0% over three years is a different conversation than a stable 5.4%. We can get the full picture with content and trends.
If you have questions about what your labs mean, what we're watching, or whether there's more we should be looking at – that's exactly what we're here for. Reach out anytime.
