Prediabetes: What Your Blood Test Numbers Mean and How to Turn It Around

Prediabetes is a warning light, not a verdict. In the US alone, more than one in three adults has it, and most don’t know. The good news is that this is the stage where small, steady changes can stop type 2 diabetes from ever developing.

Imagine a routine health check. You feel completely fine. Then the nurse says your HbA1c is “in the prediabetes range.” You’re 42, busy, and you thought diabetes was something that happened to other people. What you do in the next 12 months could decide whether you’re living with diabetes at 50, or not.

What the numbers mean

Labs and countries use slightly different cut-offs, but commonly used ranges are:

• HbA1c (average blood sugar over two to three months): prediabetes is about 5.7% to 6.4% (39 to 47 mmol/mol) in US guidance; the UK uses 6.0% to 6.4% (42 to 47 mmol/mol). 6.5% (48 mmol/mol) or above suggests diabetes.
• Fasting blood glucose: roughly 5.6 to 6.9 mmol/L (100 to 125 mg/dL) in US guidance; WHO uses 6.1 to 6.9 mmol/L for “impaired fasting glucose.”

Ask your nurse or doctor which ranges your lab uses and what your exact result was.

Who should get tested?

• Adults living with overweight, especially with weight around the waist
• People with a parent or sibling with type 2 diabetes
• People of South Asian, Black African, African Caribbean, Hispanic or Indigenous heritage, who have a higher risk at lower weights
• Anyone who had diabetes in pregnancy, or has polycystic ovary syndrome
• People with high blood pressure or high cholesterol

Prediabetes usually has no symptoms, so testing is the only way to know.

Changes proven to lower your risk

• Lose a modest amount of weight if you’re overweight. In the landmark US Diabetes Prevention Program, losing around 7% of body weight plus regular activity cut the risk of developing type 2 diabetes by more than half.
• Move more: aim for at least 150 minutes a week of moderate activity, such as brisk walking, plus some strength exercise.
• Eat for blood sugar: more vegetables, pulses, whole grains and fibre; fewer sugary drinks, sweets and refined white carbohydrates.
• Sleep and stress: poor sleep and chronic stress both affect blood sugar.
• Stop smoking, which raises the risk of diabetes and its complications.
• Join a programme: many countries offer free or low-cost diabetes prevention programmes. Ask your clinic.

But can prediabetes really be reversed?

For many people, yes: blood sugar can return to the normal range. Even if it doesn’t, lowering it delays diabetes and protects your heart, kidneys and eyes. Some people are offered medication such as metformin alongside lifestyle changes. Get your HbA1c rechecked at least once a year so you can see your progress.

Sources: US Centers for Disease Control and Prevention (Prediabetes; National Diabetes Prevention Program), American Diabetes Association Standards of Care, NHS (Prediabetes; NHS Diabetes Prevention Programme), World Health Organization. This guide is for general information and does not replace advice from your own nurse, doctor or pharmacist.