Prediabetes is a state where blood sugar is already above normal but does not yet reach the diabetes range. A kind of "yellow light": the disease is not there yet, but the body is signaling.
The main thing to know: prediabetes is reversible. At this stage a change of lifestyle can bring sugar back to normal and prevent type 2 diabetes.
Reference ranges
Prediabetes is defined by one of the markers:
| Fasting glucose | 5.6 – 6.9 mmol/L |
| Glycated hemoglobin (HbA1c) | 5.7 – 6.4% |
| Diabetes — if | glucose ≥ 7.0 or HbA1c ≥ 6.5% |
What an elevated level means
Prediabetes is usually asymptomatic — that is what makes it insidious. Sometimes there are non-specific signs: fatigue, sugar cravings, darkening of the skin in the folds (acanthosis).
Who is at risk: excess weight and visceral fat, physical inactivity, age 45+, diabetes in close relatives, hypertension, elevated triglycerides.
If sugar is in the prediabetes zone, it is not a verdict but a window of opportunity: exactly the time to act.
What a low level means
There is no such thing as "low prediabetes" — this state is defined only by sugar being above normal. Low sugar (hypoglycemia) is a separate situation, more often linked to medications or prolonged fasting.
How the test is done
It is assessed by fasting glucose and/or glycated hemoglobin (HbA1c). Glucose is drawn strictly fasting (8–12 hours); HbA1c can be taken any time and reflects the average sugar over 3 months.
With borderline numbers a doctor may order an oral glucose tolerance test.
What affects the value
- Visceral fat — a key factor in insulin resistance.
- Movement — lowers sugar and raises insulin sensitivity.
- Diet — excess sugar and refined carbohydrates worsen the numbers.
- Weight — losing even 5–7% noticeably improves sugar.
- Sleep and stress — lack of sleep and high cortisol raise glucose.
Calculate using this marker
Calculators where Prediabetes is used directly:
Frequently asked questions
Will prediabetes necessarily turn into diabetes?
No. It is a reversible state. Studies show that weight loss, regular movement and a diet lower in sugar return sugar to normal in a large share of people and markedly lower the risk of type 2 diabetes.
Which test defines prediabetes?
Fasting glucose (5.6–6.9 mmol/L) or glycated hemoglobin HbA1c (5.7–6.4%). One marker in this range is enough; the diagnosis is usually confirmed on repeat.
What should I do about prediabetes?
The main thing is lifestyle: lose weight (especially visceral fat), move more, cut sugar and refined carbohydrates, and fix your sleep. Our calculators can help you assess your metabolic risk.