Evidence guide
What Is Prediabetes? A1C, Fasting Glucose, and What to Do Next
A plain-language guide to prediabetes blood-test ranges, what the result means, and practical next questions to discuss with a clinician.
Published 2026-08-20 · Updated 2026-08-20 · Author: Prediabetes.Life
Short answer
Prediabetes means blood glucose is higher than the normal range but below the diabetes range. Common laboratory ranges are A1C 5.7%–6.4%, fasting plasma glucose 100–125 mg/dL, or a 2-hour oral glucose tolerance result of 140–199 mg/dL. A clinician should interpret the result in the context of your health and decide whether repeat or confirmatory testing is appropriate.
What blood-test ranges are used for prediabetes?
Health professionals can use A1C, fasting plasma glucose, or an oral glucose tolerance test to identify prediabetes. The tests measure glucose in different ways, so they do not always classify the same person identically.
| Test | Prediabetes range | Diabetes range |
|---|---|---|
| A1C | 5.7%–6.4% | 6.5% or above |
| Fasting plasma glucose | 100–125 mg/dL | 126 mg/dL or above |
| 2-hour oral glucose tolerance test | 140–199 mg/dL | 200 mg/dL or above |
Does prediabetes mean type 2 diabetes is inevitable?
No. Prediabetes signals increased risk, not a guaranteed outcome. Risk is influenced by several factors, and established lifestyle interventions have been shown to reduce or delay progression for many people at high risk.
The useful response is neither panic nor dismissal: understand the result, confirm what follow-up your clinician recommends, and focus on changes you can sustain.
What should I do after a prediabetes result?
- Ask your clinician what test produced the result and whether it should be repeated or confirmed.
- Review other risk factors such as family history, blood pressure, weight pattern, activity level, prior gestational diabetes, and medications with your clinician.
- Work on sustainable eating and activity habits rather than pursuing an extreme short-term plan.
- If weight loss is appropriate for you, ask what target is reasonable for your individual situation.
How often should someone with prediabetes be retested?
NIDDK states that people with prediabetes should generally be tested for type 2 diabetes every year. Your clinician may recommend a different interval based on the original result, symptoms, pregnancy status, medications, or other risk factors.
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