A1C of 5.7, 5.8 or 5.9: what it means

An A1C of 5.7, 5.8 or 5.9 percent is in the prediabetes range. It is below the 6.5 percent threshold used to diagnose diabetes, and one result by itself does not tell the whole story. A1C estimates average blood sugar over roughly the past few months, so your clinician may consider repeat testing, other glucose results and factors that can affect the test. These numbers are a useful prompt to understand your risk and choose practical habits, not a reason to panic. ADA Standards of Care describe the diagnostic thresholds and when confirmation is needed.

Is an A1C of 5.7 bad?

It is higher than the normal range, but “bad” can make the result sound more urgent or certain than it is. The American Diabetes Association defines A1C below 5.7 percent as normal, 5.7 to 6.4 percent as prediabetes, and 6.5 percent or higher as diabetes. An A1C of 5.7 is at the lower edge of the prediabetes range; 5.8 and 5.9 are also within it. The result does not mean that you have diabetes, and it cannot predict exactly what will happen to you. ADA Standards of Care

A1C result	Usual category	A practical interpretation
Below 5.7%	Normal range	Below the prediabetes cutoff
5.7% to 6.4%	Prediabetes range	Discuss risk and follow-up with your clinician
6.5% or higher	Diabetes range	Usually requires confirmation if there are no clear symptoms

These cutoffs are screening and diagnostic categories, not a personal forecast. Clinicians may repeat an abnormal test or use another test when the result and the broader clinical picture do not line up. The 2024 ADA standards say, in people without unequivocal high blood sugar, diagnosis requires two abnormal results, either from the same test at different times or from different tests. ADA Standards of Care

For context, an A1C of 5.5 is below the 5.7 percent cutoff. An “A1C of 5” is incomplete shorthand: the decimal matters, because 5.0 and 5.7 fall on different sides of that cutoff. If you want to compare A1C with the estimated average glucose in mg/dL, use the A1C calculator. A1C and a single glucose reading answer different questions, as explained in A1C vs glucose.

What does A1C measure, and what can change it?

A1C measures the share of hemoglobin, the oxygen-carrying protein in red blood cells, that has glucose attached. Since red blood cells circulate for weeks to months, the result reflects a weighted picture of recent blood sugar rather than a snapshot after one meal. It is not an exact average for every person. The International Expert Committee report describes A1C as a way to assess chronic glycemia and discusses conditions that can make results misleading. International Expert Committee

Some conditions that change red blood cell turnover or hemoglobin can affect A1C. Examples include certain anemias, recent blood loss or transfusion, some hemoglobin variants, pregnancy, and advanced kidney disease. In those settings, a clinician may interpret A1C alongside a fasting glucose or another test. Do not assume the number is wrong, but mention relevant diagnoses and recent events when reviewing it. International Expert Committee ADA Standards of Care

If an A1C result surprises you, ask whether the lab test was repeated, whether your fasting glucose or other results tell the same story, and whether any health condition could affect A1C. For more on other test types, see glucose blood tests explained and fasting blood sugar levels. A clinician can help decide when to check again; the right interval depends on your results and health history.

What to do after a result of 5.7 to 5.9

Start with a conversation, not a drastic plan. Bring the lab report and a list of medicines and supplements to your appointment. Ask what follow-up makes sense for you, including whether to repeat A1C or check fasting glucose, and how often to monitor. If you already have diabetes or take glucose-lowering medicine, do not change treatment based on this article or a single A1C result. Discuss any change with the clinician who manages your care.

Then look for manageable habits you can keep doing. In the Diabetes Prevention Program trial, 3,234 adults at high risk were assigned to a structured lifestyle program, metformin or placebo. The lifestyle program aimed for 7 percent weight loss and at least 150 minutes of weekly activity; over an average 2.8 years, diabetes incidence was 58 percent lower in that group than in the placebo group. The trial tested a sustained, supported program in a higher-risk study population. It does not promise the same result for every person, and the target is not a requirement for everyone. Knowler et al.

A decade of follow-up found that the cumulative reduction in diabetes incidence remained 34 percent for the original lifestyle group compared with placebo, although the groups were later offered lifestyle support and incidence rates during the follow-up period were similar. That is evidence for the value of durable support and habits, not a guarantee that an individual A1C will fall by a set amount. Diabetes Prevention Program Research Group

Consider a few starting points:

• Move in ways you can repeat. Walking, cycling, swimming or strength work can all be adapted to ability and health. If you have been inactive or have heart, joint or balance concerns, ask your clinician how to begin safely. The DPP used a goal of 150 minutes of activity per week as part of a structured intervention, not as an instant prescription. Knowler et al.
• Make meals satisfying and balanced. Build meals around vegetables, beans or other high-fiber foods, lean proteins and portions that work for you. Cut back on sugary drinks and frequent highly processed snacks if they are a regular part of your routine. A1C alone cannot identify which food caused a result, so avoid blaming one meal or ingredient. For practical ideas, see prediabetes foods to eat and to limit and blood sugar spikes after meals.
• If weight loss is appropriate, make the plan gradual. The DPP’s weight goal was part of a coached program for people at high risk. Weight, appetite, mobility and other conditions vary; a clinician or dietitian can help set an appropriate goal. More context is in prediabetes and weight loss.
• Track what helps, not every fluctuation. A simple log of activity, meals or follow-up labs may help you notice sustainable changes. Home glucose readings vary with timing and meals and cannot substitute for an A1C or a clinical assessment. See how to check blood sugar at home if home testing has been recommended for you.

A1C in the prediabetes range often causes no noticeable symptoms. Feeling well does not invalidate the result, and symptoms alone cannot diagnose diabetes. Seek medical advice promptly for marked thirst or frequent urination, unexplained weight loss, blurred vision, or unusual weakness, especially if symptoms are new or worsening. New or worsening symptoms deserve medical care. If a glucose meter shows a very high reading together with vomiting, confusion or trouble breathing, seek urgent medical care. Confusion or fainting with a low reading also needs urgent help. ADA Standards of Care

What about supplements?

Food, activity, sleep and follow-up deserve attention before a supplement. Supplements are not a substitute for a medical evaluation or diabetes care. Evidence for a particular ingredient does not establish that every product containing it works, and products can interact with medicines. Talk to your doctor before using one, especially if you take medications. Our blood sugar supplements comparison explains how we assess research and labels. Our scores are strict: a better score means a label aligns more closely with the evidence we reviewed, not that a product is proven to lower your A1C. See the GlucoBerry review for the highest-rated blood sugar label in our reviews. Results vary.

Next step

Write down your questions and review the result with your clinician, including whether repeat testing is appropriate. For a broader explanation of the range and follow-up, read what prediabetes A1C means.

Frequently asked questions

Is an A1C of 5.7 bad?

It is at the lower edge of the prediabetes range. It is above the normal cutoff and below the diabetes cutoff. Discuss the result in context rather than treating it as a diagnosis by itself. ADA Standards of Care

Is an A1C of 5.8 or 5.9 diabetes?

No. Both values are in the 5.7 to 6.4 percent prediabetes range. An A1C of 6.5 percent or higher is in the diabetes range, and confirmation is generally needed when a person has no clear symptoms. ADA Standards of Care

Is an A1C of 5.5 normal?

Yes. It is below the 5.7 percent prediabetes threshold. Your clinician may still consider other test results and personal risk factors. ADA Standards of Care

Can I lower an A1C of 5.7 naturally?

Some people improve glucose measures through sustained lifestyle changes, but no specific result is guaranteed. In the Diabetes Prevention Program, a structured lifestyle intervention reduced the rate of developing diabetes among adults at high risk. Discuss an appropriate plan for your own health. Knowler et al.

How soon should I repeat the test?

There is no single interval that fits everyone. Ask your clinician whether to repeat A1C or use another glucose test, and when. The answer depends on your health history, test reliability and other results. ADA Standards of Care

When should I seek medical care?

Contact a clinician for new or worsening thirst, frequent urination, blurred vision, unexplained weight loss or unusual weakness. Very high glucose with vomiting, confusion or trouble breathing, or low glucose with confusion or fainting, needs urgent care. Do not wait for another A1C if concerning symptoms are happening. ADA Standards of Care

Results vary. Talk to your doctor, especially if you take medications. New or worsening symptoms deserve medical care.