Prediabetes

Diagnosed with prediabetes?
We’re here to help.

Find Out More

What Is Prediabetes? Understanding Your Results and Next Steps

Being told you have prediabetes can feel unsettling, especially if all you received was a short phone call or a letter. Prediabetes isn’t diabetes, and there’s a lot you can do from here. This page explains what your result means, what usually happens next, and how diet and lifestyle changes can help.

Prediabetes means your blood sugar is higher than normal but below the diabetes range. In the UK it’s usually diagnosed with an HbA1c of 42-47 mmol/mol (6.0-6.4%). It raises your chance of developing type 2 diabetes, but many people can lower their risk with changes to diet, activity and weight.

Prediabetes: Blood Sugar Levels and HbA1c Ranges (UK Units)

Blood sugar is commonly measured by the HbA1c test, which reflects your average blood glucose levels over the past two to three months. In the UK, HbA1c is reported in mmol/mol. 

HbA1c Range (mmol/mol) – What It Means:

  • <42 – Normal
  • 42 – 47 At risk (Prediabetes)
  • 48 or above Diabetes (diagnosis)

An HbA1c between 42 and 47 mmol/mol (6.0–6.4%) means your blood sugar is higher than normal but not high enough for a diabetes diagnosis. This is often called prediabetes or non-diabetic hyperglycaemia. This is an important warning sign that you are at increased risk of developing type 2 diabetes.

Diabetes and prediabetes are increasingly common in the UK. Over 4.6 million people in the UK have been diagnosed with diabetes, with around 90% of these cases being type 2 diabetes and 8% type 1 diabetes [Diabetes UK, diabetes.org.uk].

Nearly 1.3 million people are believed to be living with undiagnosed type 2 diabetes. An estimated 6.3 million people in the UK have prediabetes (non-diabetic hyperglycaemia), meaning their blood sugar levels are higher than normal but not yet in the diabetes range. In total, more than 12 million people in the UK or about one in five adults are living with diabetes or prediabetes [Diabetes UK, diabetes.org.uk].

Without proper management, diabetes can lead to serious complications including heart failure, stroke, heart attack, and amputations. 

If you have a raised blood sugar or HbA1c in the prediabetes range, it is a warning sign. However, with lifestyle changes and support, you can often reduce your risk and even reverse prediabetes before it progresses to type 2 diabetes. Regular monitoring and early intervention are essential to protect your long-term health.

Does Prediabetes have Symptoms?

Prediabetes doesn’t usually cause noticeable symptoms. This means you can have higher than normal blood glucose (sugar) levels without feeling unwell or noticing any changes in your health. Many people only discover they have prediabetes following a blood test arranged by their GP or as part of a health check.

Although prediabetes usually has no symptoms, it’s important to recognise possible symptoms of type 2 diabetes. These can include:

  • Feeling unusually thirsty

  • Needing to pass urine more often, particularly at night

  • Feeling more tired than usual

  • Losing weight without trying

  • Blurred vision

  • Cuts or wounds that take longer to heal

  • Repeated genital itching or thrush

These symptoms do not necessarily mean you have diabetes, but you should see your GP if you experience them. A blood test can help establish whether your blood glucose levels are within the normal range, the prediabetes range or the diabetes range.

If you’ve been diagnosed with prediabetes, don’t wait for symptoms before taking action. Making practical changes to your diet, physical activity and other lifestyle habits can help improve your blood glucose levels and reduce your risk of developing type 2 diabetes.

Can Prediabetes be Reversed?

Yes, it is possible for blood glucose levels to return to the normal range if you have prediabetes, although this doesn’t happen for everyone. This is sometimes described as reversing prediabetes.

In the UK, prediabetes is commonly identified by an HbA1c blood test result of 42–47 mmol/mol. An HbA1c result below 42 mmol/mol is within the normal range, while a result of 48 mmol/mol or above is in the diabetes range and requires appropriate clinical assessment.

Making sustainable lifestyle changes can help lower blood glucose levels and reduce the risk of developing type 2 diabetes. Depending on your individual circumstances, helpful changes may include:

  • Improving your diet: Eat a balanced variety of foods, including vegetables, fruit, wholegrains, beans and other sources of fibre.

  • Being more physically active: Find activities you enjoy and build movement into your daily routine. Even small changes can be a useful starting point.

  • Considering weight management if appropriate: If you’re living with overweight or obesity, losing weight may help improve blood glucose levels. However, not everyone with prediabetes needs to lose weight.

  • Building sustainable habits: Focus on realistic changes you can maintain rather than restrictive diets or quick fixes.

There is no guaranteed way to reverse prediabetes, and your progress will depend on a range of individual factors. Even if your HbA1c doesn’t return to the normal range, improving your diet and lifestyle can still benefit your health and help reduce your risk of progressing to type 2 diabetes.

What to Eat: Lifestyle and Dietary Habits

Your lifestyle choices play a crucial role in your risk of developing type 2 diabetes. A sedentary lifestyle, spending long periods sitting or being inactive is linked to higher risk, even if you meet weekly exercise recommendations. Regular physical activity, such as brisk walking for at least 2.5 hours per week, can help reduce your risk.

Diet is equally important. Diets high in processed foods, sugary drinks, refined carbohydrates (like white bread and rice), and red or processed meats are associated with increased risk. Conversely, a healthy diet rich in fruit, vegetables, whole grains, and pulses can help lower your risk and support weight management.

Other lifestyle factors include:

  • Limiting alcohol intake to no more than 14 units per week, spread over several days
  • Not smoking, as diabetes increases the harmful effects of tobacco
  • Ensuring good sleep, as both insufficient and excessive sleep can increase risk

For more information on diet, see our Prediabetes Diet & Healthy Eating​ page.

How We Can Help

We provide personalised support for people with prediabetes, those looking to manage their weight, and individuals taking or coming off weight-loss medication. Our aim is to help you make practical, sustainable changes to your eating habits that fit your lifestyle and support your long-term health.

Please see our assessment page or click on ‘Prediabetes Assessment’ to get started.

Prediabetes Assessment

Useful Information

More information on Diabetes – Diabetes UK: What is diabetes? | Getting to know the basics | Diabetes UK  

Diabetes Symptoms – Diabetes UK: Symptoms of diabetes | Type 1 and Type 2 | Diabetes UK