Signs of Prediabetes — Early Warning Signs and What to Do (2026)
- 1 in 3 UK adults and 88 million Americans have prediabetes — 84% don't know it
- Prediabetes usually causes no obvious symptoms — it is detected through blood tests only
- Dark skin patches (acanthosis nigricans) are one of the only visible signs
- Prediabetes is fully reversible — lifestyle changes reduce progression risk by 58%
- If untreated, prediabetes progresses to Type 2 diabetes within 3–10 years in most people
What Is Prediabetes?
Prediabetes is a metabolic state where blood glucose levels are higher than normal but not yet high enough to be diagnosed as Type 2 diabetes. It represents a critical window of opportunity — the condition is reversible through lifestyle changes, but only if caught and acted upon.
Why Prediabetes Usually Has No Symptoms
Unlike Type 2 diabetes (which can cause thirst, urination, and fatigue at sufficiently high blood glucose), prediabetes blood glucose levels are elevated enough to cause progressive organ damage but not high enough to trigger the classic diabetes symptoms. This is exactly why it is so dangerous — and why blood testing is the only reliable way to detect it.
The Few Visible Signs
Acanthosis Nigricans
The most common visible indicator of insulin resistance and prediabetes: velvety, darkened patches of skin in body folds — the back of the neck, armpits, and groin. Caused by elevated insulin stimulating skin cell growth. Particularly common in people with darker skin tones, children with obesity, and women with PCOS.
Skin Tags
Multiple skin tags (acrochordons) — particularly in the armpits and neck — are associated with insulin resistance and are more common in people with prediabetes and Type 2 diabetes.
Who Is Most at Risk?
| Risk Factor | Increase in Prediabetes Risk |
|---|---|
| BMI above 25 (or 23 for Asian adults) | 3–4× higher |
| Physical inactivity | 2–3× higher |
| Family history of Type 2 diabetes | 2–3× higher |
| PCOS | 5–10× higher lifetime risk |
| Previous gestational diabetes | 7× higher long-term |
| Age over 45 | Moderate increase |
| Ethnicity (South Asian, African, Hispanic) | Higher risk at lower BMI |
How to Reverse Prediabetes
The Diabetes Prevention Program protocol that achieved 58% risk reduction involved three components, all of which are achievable without medication:
- Lose 5–7% of body weight: For a 90 kg person, this is just 4.5–6.3 kg — achievable in 3–4 months with a moderate calorie deficit
- 150 minutes of moderate exercise per week: Five 30-minute brisk walks per week meets this target
- Dietary changes: Reduce refined carbohydrates and saturated fat; increase fibre from vegetables, whole grains, and legumes