What does prediabetes mean?
Your blood sugar is above normal, but below type 2. On an HbA1c test (your average blood sugar), that’s 42 to 47 mmol/mol. It can go back to normal, but not on its own.
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What does prediabetes mean?
It means your blood sugar is higher than it should be, but not high enough to be type 2 diabetes. It’s also called borderline diabetes.
The HbA1c test shows your average blood sugar. On it, prediabetes is 42 to 47 mmol/mol.
Below 42 is normal. 48 or above is the range for type 2.
- Below 42 mmol/molNormal.
- 42 to just under 48 mmol/molPrediabetes. Your GP should offer a course.
- 48 mmol/mol or aboveThe range for type 2 diabetes.
Sources: Diabetes UK; NICE PH38
Had a fasting blood sugar test instead? NICE counts 5.5 to 6.9 mmol/L as high risk.
Think of it as an amber light. It isn’t red, and it doesn’t mean you’ll reach red. But it does mean a high risk of type 2, so it’s the time to make changes.
Feel fine? There aren’t usually any symptoms, and it affects around one in 12 people. It’s more common with extra weight, but it can affect people of a healthy weight too.
Ask your GP for your exact number, and which test it came from. More on each test in our pre-diabetes blood test guide.
Does prediabetes go away?
Not on its own. Diabetes UK says you’ll need to make health changes.
Then it can go back below 42. That’s called reversing prediabetes.
It may not go all the way back. But any fall helps. It can lower your cholesterol and blood pressure, and help stop your HbA1c creeping up to 48.
Changes do work. A US trial followed 3,234 adults with raised blood sugar. A lifestyle programme cut new cases of type 2 by 58% over 2.8 years, compared with dummy pills.
People in that trial aimed to lose 7% of their weight and do 150 minutes of activity a week. Their average BMI (a score of weight for height) was 34.
Give it time. Reversing it in three months is unlikely to be realistic. And once you’re back to normal, keep your yearly test, as levels can creep back up.
What does the NHS do for prediabetes?
What usually happens after a prediabetes result
- 1
Blood test
An HbA1c or fasting blood sugar test confirms it.
- 2
A free course
Your GP should refer you to a type 2 prevention course or advice.
- 3
Yearly check
A blood test at least once a year, and a weight check.
- 4
Medicine, sometimes
Metformin, or a weight loss medicine depending on your BMI, if changes haven’t worked.
Sources: Diabetes UK; NICE PH38
In England, the course is the Healthier You programme. It lasts nine months, in a group or online, and you choose which.
It cuts the risk of type 2 by more than a third for people who finish it. If places are short, NICE puts people with an HbA1c of 44 to 47 first.
Metformin is a tablet that helps insulin, the hormone that controls blood sugar, work better. NICE leaves it to your doctor’s judgement. It may come up if your results get worse despite a course, or you can’t do one, especially with a BMI over 35.
Never stop or change a prescribed medicine without your prescriber. Not offered a course? Ask your GP practice, as it makes the referral.
How can I reverse prediabetes?
If you carry extra weight, losing some is likely to have the biggest impact. Even 1% to 9% of your weight can help lower your average blood sugar. Check where you are with our BMI calculator.
| Your weight | 1% is | 9% is |
|---|---|---|
| 70 kg | 0.7 kg | 6.3 kg |
| 80 kg | 0.8 kg | 7.2 kg |
| 90 kg | 0.9 kg | 8.1 kg |
| 100 kg | 1 kg | 9 kg |
Source: Diabetes UK
A healthy weight already? Changes to food and activity can still help.
Underweight? Losing more isn’t safe, so talk to your GP.
Six changes that help with prediabetes
- Eat more fruit, veg, wholegrains like oats and wholemeal bread, and pulses like chickpeas and lentils.
- Cut back on sugary drinks and processed foods high in salt and sugar, like bacon, chips, cheese, sweets and biscuits.
- Walk, or do something that leaves you out of breath, for at least 2.5 hours across the week.
- Break up long spells of sitting or lying down, such as in front of the TV.
- If you smoke, get support to stop.
- Aim for good quality sleep.
Sources: Diabetes UK; NHS
Finding it hard? Try one small change a week.
Talk to your GP before you change your diet, lose weight or start a new activity, as Diabetes UK advises. Above all, check before a very strict, low-calorie diet. It may not be suitable if you take diabetes medicine.
More ideas: insulin resistance diet, how to lower HbA1c and walking after meals.
When to speak to a GP
Most people with prediabetes do not have symptoms. Book an appointment if:
- You have signs of type 2: feeling very tired, peeing more than usual, feeling thirsty all the time or losing weight without trying. Also blurred vision, cuts that heal slowly, itching around your penis or vagina, or thrush that keeps coming back.
- You’re at higher risk: white and over 40, over 25 and South Asian, Chinese, Black African or Black Caribbean, a parent, brother or sister has type 2, you’re overweight and not very active, or you have a condition that raises your risk, such as high blood pressure.
- You have prediabetes but haven’t had a blood test in the last year, or weren’t offered a course.
- You’re underweight, or you take diabetes medicine and want to try a very strict, low-calorie diet.
- You had diabetes in pregnancy (gestational diabetes). Diabetes UK says to keep going for your yearly test.
Aged 40 to 74 with no existing health condition? In England, ask your GP surgery or pharmacy for a free NHS Health Check. Risk also rises with age, family history, extra fat around your middle and your ethnic background.