What A1C level means you have prediabetes—and what to do next
Key Takeaways
Prediabetes is diagnosed when your hemoglobin A1C falls between 5.7 % and 6.4 %. Below 5.7 % is considered normal glucose regulation, while 6.5 % or higher meets criteria for type 2 diabetes. If your value lands in the 5.7–6.4 % window, you have an elevated risk—up to 70 % lifetime—of progressing to diabetes, but timely lifestyle changes can often return readings to the healthy range.
What exact A1C range defines prediabetes?
An A1C test reflects your average blood glucose over the past 2–3 months. According to the American Diabetes Association, a value of 5.7 %–6.4 % is classified as prediabetes. Higher than 6.4 % signals diabetes, while lower than 5.7 % is normal. “Even a single result of 5.7 % is a sign your body’s insulin response is under stress,” notes Sina Hartung, MMSC-BMI.
- The 5.7 % cutoff comes from population-wide risk dataPeople whose A1C rises just 0.1 % above 5.6 % have a statistically significant increase in future diabetes risk, so 5.7 % was chosen as the earliest reliable warning point.
- Values between 6.0 % and 6.4 % carry the highest short-term dangerRoughly 25 % of individuals with A1C 6.0 %–6.4 % progress to diabetes within three years if no action is taken.
- Laboratories round to the nearest tenthIf your lab report shows 5.65 %, it will display as 5.7 %, automatically classifying you as prediabetic.
- Finger-stick glucose cannot replace A1CA normal fasting glucose today does not rule out prediabetes—it only captures one moment, whereas A1C shows a months-long average.
- Four out of five people with prediabetes don’t know they have itThe CDC estimates that 80 % of U.S. adults whose A1C falls between 5.7 % and 6.4 % are unaware they have prediabetes, underscoring the importance of routine screening. (CDC)
- Up to 30 % of prediabetic adults develop diabetes within five years without lifestyle changesNIDDK reports that, without weight loss and increased physical activity, roughly 15 %–30 % of individuals in the prediabetes A1C range will progress to type 2 diabetes within five years. (NIDDK)
Which symptoms or lab patterns should prompt urgent care if your A1C is in the prediabetes range?
Prediabetes itself usually has no symptoms, but certain red flags suggest blood sugar may already be spiking into diabetic territory. “Rapid weight loss or persistent yeast infections mean glucose is likely well beyond the prediabetes zone,” warns the team at Eureka Health.
- Blurred vision that develops over weeksSwings in blood glucose pull fluid into the lens of the eye; sudden blurring signals levels high enough to harm the retina.
- Fasting glucose repeatedly above 126 mg/dLTwo morning readings over this threshold meet the definition of diabetes and warrant prompt clinician review.
- Night-time urination more than twiceThe kidneys flush excess glucose, leading to nocturia; if this starts suddenly, get checked within days.
- Numbness or tingling in feetPeripheral nerves are sensitive to glucose spikes; early neuropathy can appear even before overt diabetes.
- Unintentional weight loss despite adequate eatingDropping pounds without trying indicates the body is breaking down fat and muscle because glucose is not getting into cells; Elo Health lists unintentional weight loss among diabetes-level warning signs that should prompt prompt medical review. (Elo)
- Constant thirst and daytime polyuriaElo Health notes that markedly elevated sugars cause increased thirst and frequent urination during the day, a combination that signals glucose has moved beyond prediabetes and warrants same-week evaluation. (Elo)
How often should you re-check A1C after a prediabetes result?
The ideal monitoring interval depends on your exact number and risk factors. “For most patients, six months is reasonable; sooner if you’re already near 6.4 %,” says Sina Hartung, MMSC-BMI.
- A1C 5.7 %–5.9 % calls for annual testingIf you have no additional risk factors, yearly monitoring is usually safe.
- A1C 6.0 %–6.4 % benefits from 3–6 month checksFrequent feedback helps you and your clinician see if lifestyle changes are working before diabetes develops.
- Family history or gestational diabetes halves the retest intervalHigh-risk groups should test every three months even with lower prediabetes numbers.
- Continuous glucose monitors (CGMs) can fill the gapsA 14-day CGM study shows daily patterns and can be ordered by many primary-care practices.
- Most major guidelines call for an A1C repeat every 12–24 months if levels stay stableCDC, ADA and Mayo Clinic all advise people with prediabetes to have their A1C re-checked at least once every one to two years when no new risk factors emerge. (CDC)
- A 2–3-month follow-up can show whether lifestyle changes are workingHarvard Health notes that retesting HbA1c after roughly 8–12 weeks can reveal early drops because red blood cells turn over in about 90 days. (HH)
- CDC: https://www.cdc.gov/diabetes/diabetes-testing/prediabetes-a1c-test.html
- ADA: https://diabetes.org/about-diabetes/diagnosis
- HH: https://www.health.harvard.edu/diseases-and-conditions/hemoglobin-a1c-hba1c-what-to-know-if-you-have-diabetes-or-prediabetes-or-are-at-risk-for-these-conditions
- Mayo: https://www.mayoclinic.org/diseases-conditions/prediabetes/diagnosis-treatment/drc-20355284
Which daily habits are proven to bring A1C back to normal?
Lifestyle changes remain the first-line treatment and can cut progression to diabetes by 58 %. “Small, consistent steps beat crash diets every time,” emphasizes the team at Eureka Health.
- Losing 7 % of body weight lowers A1C about 0.4 %In the landmark Diabetes Prevention Program, this modest weight loss was enough to normalize glucose in many participants.
- 150 minutes of brisk walking per week is a minimumAim for 30 minutes, five days a week; break it into 10-minute bouts if needed.
- Prioritize 25 g of fiber dailyFiber slows carbohydrate absorption; swap white rice for quinoa, and add beans or lentils to meals.
- Limit sugary drinks to zeroOne 12-oz soda raises average glucose for up to 24 hours; replacing with water can drop A1C by 0.2 % over three months.
- Sleep at least 7 hours nightlyShort sleep increases insulin resistance by roughly 15 % the next day.
- Fill half your plate with non-starchy vegetablesThe Elo Health guide advises dedicating 50 % of each meal to non-starchy produce to blunt glucose spikes and encourage lower A1C. (Elo)
- Quit smoking to ease insulin resistanceMayo Clinic lists smoking cessation among the core lifestyle steps to bring blood sugar back to normal because tobacco use makes it harder for insulin to work. (Mayo)
What other tests and treatments might your clinician consider?
An A1C is only part of the metabolic picture. “Checking lipids and liver enzymes at the same visit helps reveal hidden cardiovascular risk,” says Sina Hartung, MMSC-BMI.
- Fasting lipid panel identifies accompanying dyslipidemiaUp to 80 % of people with prediabetes also have elevated triglycerides.
- ALT over 35 U/L may point to fatty liverNon-alcoholic fatty liver often travels with insulin resistance and accelerates diabetes development.
- Oral glucose tolerance test (OGTT) can unmask higher spikesAbout 15 % of patients with normal A1C but high 2-hour OGTT glucose already meet diabetes criteria.
- Metformin is sometimes started at A1C 6.0 %–6.4 %Guidelines allow low-dose metformin for high-risk adults under 60 or women with prior gestational diabetes, but a prescription decision is individualized.
- Repeat A1C every 1–2 years to monitor riskThe CDC recommends retesting A1C within 1–2 years after a prediabetes result so clinicians can detect progression to diabetes early. (CDC)
- 7% weight loss plus 150 minutes of exercise reduces diabetes onsetADA notes that losing about 7 % of body weight and exercising moderately (30 minutes a day, five days a week) lowers the risk of type 2 diabetes for people with prediabetes. (ADA)
Frequently Asked Questions
Yes. About one-third of people with A1C 5.7 %–6.4 % still show fasting glucose under 100 mg/dL.
Very-low-carb diets can lower A1C, but long-term success comes from sustainable eating patterns rather than extreme restriction.
FDA-cleared home kits are usually within ±0.2 %, but a lab draw is recommended for diagnosis.
Improvements often show within three months, the time span A1C reflects.
Kids with obesity or a family history of diabetes should start screening at age 10 or at puberty, whichever comes first.
Certain GLP-1 receptor agonists lower A1C and weight but are generally reserved for people who already have type 2 diabetes.
Most U.S. plans cover two A1C measurements per year in people with prediabetes; more frequent tests may require prior authorization.
Fructosamine measures average glucose over 2–3 weeks and can be useful if you have a condition that alters red blood cell turnover.
- ADA: https://diabetes.org/about-diabetes/diagnosis
- CDC: https://www.cdc.gov/diabetes/diabetes-testing/prediabetes-a1c-test.html
- NIDDK: https://www.niddk.nih.gov/health-information/diagnostic-tests/a1c-test
- Elo: https://www.elo.health/biomarkers/hba1c-overview/60/
- Elo: https://www.elo.health/biomarkers/hba1c-overview/61/
- HH: https://www.health.harvard.edu/diseases-and-conditions/hemoglobin-a1c-hba1c-what-to-know-if-you-have-diabetes-or-prediabetes-or-are-at-risk-for-these-conditions
- Mayo: https://www.mayoclinic.org/diseases-conditions/prediabetes/diagnosis-treatment/drc-20355284
- Elo: https://elo.health/blogs/hba1c/6-2
- ADA: https://diabetes.org/diabetes/a1c/diagnosis
- NIDDK: https://www.niddk.nih.gov/health-information/professionals/clinical-tools-patient-management/diabetes/diabetes-prediabetes