What does an A1c of 5.7 mean?
Where 5.7 sits
| A1c | Category | Average glucose |
|---|---|---|
| Below 5.7% | Normal | Below 117 mg/dL |
| 5.7–6.4% | Prediabetes | 117–137 mg/dL |
| 6.5% or above | Diabetes | 140 mg/dL or above |
5.7% is the first value in the prediabetes band — the bottom of it, not the middle.
What it does and does not mean
It is not diabetes. That threshold is 6.5%, and it needs two abnormal results to confirm.
It probably causes no symptoms. Prediabetes sits well below the level at which the kidneys start spilling glucose into urine, so the classic thirst and frequent urination usually do not appear. Feeling completely well is the normal case.
It is a line, not a cliff. 5.7% is not biologically different from 5.6%. These thresholds are drawn across a continuum for practical purposes. Someone at 5.7% and someone at 5.6% are in essentially the same physiological state, with different labels.
It is a genuine signal about direction. Prediabetes is one of the strongest predictors of developing type 2 diabetes, and cardiovascular risk is already modestly elevated in this range rather than starting at 6.5%.
The trend matters more than the value
This is the most useful thing to take from a result of 5.7%.
Someone at 5.7% who was 5.6% last year is in a different situation from someone at 5.7% who was 6.1% last year and has been working at it. The number is identical; the trajectory is opposite.
If you have had A1c tests before, dig them out. Direction of travel tells you more than any single reading, and it is the thing most likely to be missing from the conversation.
What to do about it
Confirm it. A single result near a threshold deserves a second test. Ask for a fasting glucose alongside the next A1c — the two answer slightly different questions and disagreement between them is informative.
Check whether the A1c is even reliable for you. Anemia, recent blood loss, chronic kidney disease, pregnancy and sickle cell trait all distort the result. If you have any of those, the number may not mean what it appears to.
Act, because this is the stage where acting works. In the Diabetes Prevention Program, 5 to 7% weight loss plus 150 minutes of weekly activity reduced progression to type 2 diabetes by 58% — better than metformin in the same trial. For someone at 200 lb that is 10 to 14 lb.
The changes with the best evidence: walk after meals, eat vegetables and protein before starch, add fibre, protect your sleep, and get sleep apnea investigated if the signs are there.
Ask about a structured prevention program. They exist, they are often free or low cost in the US, and they consistently outperform being told to eat better and come back next year.
Re-test in a year at minimum. Our A1c levels chart covers what each percentage means and the situations where the test misleads, and prediabetes symptoms covers who should be screened and why symptoms are a poor guide.
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