An A1c of 5.7% is not dangerous, but it’s not normal either. It sits exactly at the threshold where the American Diabetes Association classifies blood sugar levels as prediabetes. The prediabetes range runs from 5.7% to 6.4%, with anything below 5.7% considered normal and 6.5% or higher qualifying as type 2 diabetes. So at 5.7%, you’re at the very lowest edge of prediabetes, which is actually a favorable position to be in because it means you’ve caught elevated blood sugar early.
What a 5.7% A1c Actually Means
Your A1c reflects your average blood sugar over the past two to three months. It measures the percentage of your red blood cells that have glucose attached to them. The higher your blood sugar runs day to day, the more glucose sticks to those cells.
At 5.7%, your estimated average blood sugar works out to about 117 mg/dL, using the standard conversion formula. For comparison, a normal fasting blood sugar is under 100 mg/dL. So your body is running slightly higher than it should, meaning your cells aren’t responding to insulin as efficiently as they once did. This is called insulin resistance, and it’s the engine that drives prediabetes toward type 2 diabetes if nothing changes.
The Risk of It Getting Worse
Prediabetes does not automatically become diabetes. But without intervention, the risk is real. Research tracking large populations found that roughly 4 out of every 100 people with prediabetes progress to type 2 diabetes each year. Over five years, that rate stays fairly steady, meaning the risk accumulates the longer blood sugar stays elevated.
Being at 5.7% rather than, say, 6.2% works in your favor. The closer your A1c is to the diabetes threshold of 6.5%, the higher your annual risk of crossing it. At the low end of the prediabetes range, you have more time and more room to reverse course. But “low-risk prediabetes” is still prediabetes, and the trajectory matters more than any single number. If your A1c was 5.4% a year ago and it’s 5.7% now, that upward trend deserves attention.
Damage Can Start Before Diabetes
One common assumption is that health complications only begin once someone has full diabetes. That’s not entirely true. A systematic review of microvascular complications in prediabetes found that people with A1c levels between 5.7% and 6.4% had significantly more retinopathy (damage to the small blood vessels in the eye) than those with lower levels. The researchers noted that screening for retinal changes may be worth considering at A1c levels of 5.7% and above.
Evidence for kidney damage and nerve damage at the prediabetes stage is less clear, with too few studies to draw firm conclusions. But the retinopathy findings suggest that even mildly elevated blood sugar isn’t completely harmless to your body over time. This doesn’t mean you should panic at 5.7%. It means this number is worth taking seriously rather than dismissing.
Physical Signs You Might Notice
Most people with prediabetes feel completely fine, which is why it’s typically caught through routine blood work rather than symptoms. But there is one visible sign worth knowing about: dark, velvety patches of skin that appear in body creases like the neck, armpits, or groin. This condition, called acanthosis nigricans, is a direct sign of insulin resistance and shows up frequently in people with prediabetes, particularly those carrying extra weight. If you’ve noticed these patches, they’re not a skin problem. They’re a metabolic signal.
How to Bring Your A1c Back Down
The most encouraging thing about a 5.7% A1c is that prediabetes is highly reversible at this stage. The landmark Diabetes Prevention Program, a major clinical trial funded by the National Institutes of Health, showed that lifestyle changes reduced the risk of developing type 2 diabetes by 58% compared to doing nothing. That’s a larger effect than medication produced in the same study.
The specific targets that produced those results were straightforward: participants lost 7% of their body weight and exercised 150 minutes per week. For someone weighing 200 pounds, that’s 14 pounds. The exercise didn’t need to be intense. Brisk walking counted. And these results showed up within about three years.
What matters most in practical terms is reducing the insulin resistance that’s driving your blood sugar up. The two most effective levers are losing a modest amount of weight (even 5% makes a measurable difference) and regular physical activity, which improves how your muscles use glucose independently of weight loss. Cutting back on refined carbohydrates and sugary drinks helps by reducing the blood sugar spikes your body has to manage throughout the day.
At 5.7%, medication is rarely part of the conversation. This is a stage where your body still produces plenty of insulin. It just isn’t using it efficiently. That inefficiency responds well to the changes above, and many people bring their A1c back below 5.7% within six months to a year of consistent effort.
How Often to Recheck
A single A1c reading gives you a snapshot, but tracking it over time tells you whether things are improving, stable, or heading in the wrong direction. Most guidelines recommend rechecking A1c at least once a year if you’re in the prediabetes range. If you’ve made significant changes to your diet or activity level, retesting at three to six months can show you whether those changes are working, since A1c reflects roughly the last 90 days of blood sugar.
Keep in mind that certain conditions can skew A1c results. Anemia, recent blood loss, and some hemoglobin variants can make the number read artificially high or low. If your A1c doesn’t match what your fasting blood sugar or glucose tolerance test shows, it’s worth discussing that discrepancy with your provider.