Prediabetes: What Your Numbers Mean and What to Do Next

The three main tests

Doctors usually use one of three tests. Each has its own cut-off points, and your doctor may repeat a test before making a diagnosis.

• HbA1c (A1C): reflects average blood sugar over about 2–3 months. 5.7%–6.4% is generally considered prediabetes; 6.5% or higher suggests diabetes.
• Fasting plasma glucose: measured after at least 8 hours without food. 100–125 mg/dL (5.6–6.9 mmol/L) is the prediabetes range.
• Oral glucose tolerance test (OGTT): glucose measured 2 hours after a sugary drink. 140–199 mg/dL (7.8–11.0 mmol/L) indicates prediabetes.

Why it matters

Without changes, a meaningful share of people with prediabetes go on to develop type 2 diabetes within several years. Higher blood sugar over time is also linked with heart disease and stroke, even before diabetes is diagnosed.

The encouraging part: large studies such as the US Diabetes Prevention Program found that modest weight loss and regular activity cut the risk of progressing to type 2 diabetes by more than half in participants.

Practical steps that make a difference

You don't need a perfect plan. Small, steady changes add up.

• Aim for about 150 minutes of moderate activity a week, such as brisk walking.
• If you carry extra weight, losing 5–7% of your body weight can meaningfully improve blood sugar.
• Build meals around vegetables, legumes, whole grains and lean protein; limit sugary drinks.
• Prioritise 7–9 hours of sleep — short sleep worsens insulin sensitivity.
• Ask your doctor how often to retest, often once a year.

When to talk to a doctor

If you have risk factors — family history, being over 35, a history of gestational diabetes, or high blood pressure — ask about screening. Seek prompt care if you notice extreme thirst, frequent urination, blurry vision or unexplained weight loss, as these can be signs of diabetes.

Related reading