An A1c of 5.7% is not dangerous, but it is a warning sign. It sits right at the threshold where blood sugar management shifts from normal to a category called prediabetes. According to the American Diabetes Association’s 2025 standards, prediabetes is defined as an A1c between 5.7% and 6.4%, which means 5.7% is the earliest possible prediabetes reading.
That placement matters. You’re not in crisis territory, but your body is starting to handle sugar less efficiently than it should. The good news is that at 5.7%, the process is highly reversible.
What 5.7% Actually Means for Your Body
The A1c test measures how much sugar has attached to your red blood cells over the past two to three months. It’s a longer-term snapshot than a single blood sugar reading, which can swing based on what you ate that morning. Using the standard conversion formula, an A1c of 5.7% translates to an estimated average blood glucose of about 117 mg/dL. For comparison, a normal fasting blood sugar is under 100 mg/dL.
At this level, your cells are becoming less responsive to insulin, the hormone that moves sugar out of your blood and into your cells for energy. Your pancreas compensates by producing more insulin, but the system is under strain. This is called insulin resistance, and it’s the engine behind prediabetes.
Health Risks Even Without Diabetes
One common misconception is that prediabetes only matters if it turns into type 2 diabetes. That’s not the case. Prediabetes carries its own set of health risks, even if your blood sugar never climbs higher.
People with prediabetes have a 15% greater risk for cardiovascular disease compared to people with normal blood sugar. The slightly elevated sugar levels contribute to fatty plaque buildup in your arteries over time, raising your chances of heart attack and stroke. Prediabetes also puts extra strain on your kidneys as they work harder to filter sugar from the blood. Studies have found that people with prediabetes are up to twice as likely to develop chronic kidney disease, and the risk increases the longer blood sugar stays elevated.
Your liver takes a hit too. Elevated glucose causes the body to convert excess sugar into fat, and some of that fat gets stored in the liver. Insulin resistance also impairs the liver’s ability to break down fats normally, compounding the problem. This is the pathway to fatty liver disease, which often produces no symptoms until significant damage has occurred.
How Likely Is It to Progress to Diabetes?
Not everyone with an A1c of 5.7% develops type 2 diabetes. But without changes, the odds aren’t in your favor. Roughly 5% to 10% of people with prediabetes progress to type 2 diabetes each year, and up to 70% will eventually develop it over their lifetime if nothing changes. At 5.7%, you’re at the mild end of that risk spectrum, which gives you the most room to course-correct.
What Moves the Number Down
The most effective intervention for prediabetes is weight loss through diet and physical activity. Losing just 5% to 7% of your body weight, which is 10 to 14 pounds for someone who weighs 200 pounds, has been shown to cut the risk of progressing to type 2 diabetes by more than half. That’s a more powerful effect than most medications.
The changes that matter most are straightforward. Reducing refined carbohydrates and added sugars lowers the glucose load your body has to process. Regular physical activity, even 150 minutes a week of brisk walking, improves insulin sensitivity directly by helping your muscles absorb glucose without needing as much insulin. These two changes also tend to bring down blood pressure and cholesterol, which offsets the extra cardiovascular risk that comes with prediabetes.
For people at 5.7%, these lifestyle shifts alone are often enough to bring the number back below the prediabetes threshold. An A1c in the range of 5.0% to 5.6% is considered normal.
When to Retest
After a 5.7% result, the standard recommendation is to retest every one to three years. If you make significant lifestyle changes, your doctor may want to check sooner to see whether your numbers are trending in the right direction. A single A1c test is a snapshot, so tracking the trend over time gives a much clearer picture of where your metabolism is heading.
When the Test Itself May Be Off
A1c results aren’t always perfectly accurate. Several conditions can push the number falsely higher or lower, including severe anemia, kidney failure, liver disease, and blood disorders like sickle cell anemia or thalassemia. Certain medications, including opioids and some HIV drugs, can also skew results. Blood loss, recent transfusions, and pregnancy (early or late) are additional factors. If any of these apply to you, your result may not reflect your true average blood sugar, and a different testing method may be more reliable.
For most people, though, a 5.7% reading is accurate and meaningful. It’s your body’s early alert system doing exactly what it should: giving you time to act before the problem gets harder to fix.