What is prediabetes?

Prediabetes means that your blood sugars are higher than usual, but not high enough for you to be diagnosed with type 2 diabetes. It also means that you are at high risk of developing type 2 diabetes. You are unlikely to be experiencing any symptoms with prediabetes.

Prediabetes is also sometimes called borderline diabetes. Higher than normal blood sugars can be detected via blood tests. The medical terms for higher-than-normal blood sugars are:

• Impaired Fasting Glucose (IFG)
• Impaired Glucose Tolerance (IGT)
• Impaired Glucose Regulation (IGR)
• Non-diabetic hyperglycaemia 

These tests are a mix of fasting or non-fasting and they all help your healthcare team to understand your risk of developing type 2 diabetes. So, if you’ve been told you have any of these, knowing this is the first step to being able to do something about it. And for many people there are things you can do to reduce your risk of type 2 diabetes.

Diagnosing prediabetes

If you’re worried about prediabetes you could call your GP surgery and ask for a blood test. The most common test will be checking your HbA1c levels which is your average blood glucose (sugar) levels for the last two to three months. If your HbA1c level is between 42mmol/mol (6%) – 47mmol/mol (6.4%) this means it is higher than normal and you are at risk of developing type 2 diabetes. 

Prediabetes symptoms

Prediabetes doesn’t have any symptoms. If you start to have any of the symptoms of type 2 diabetes it means you have probably already developed it.

So it’s important to know the risk factors and what support is available to help you prevent or delay type 2 diabetes.

A lot of people don’t get any symptoms when it comes to type 2 diabetes, or don’t notice them. But you may notice:

• going to the toilet more often, especially at night
• feeling more tired, because your body can't get enough glucose in to your cells for energy
• losing weight without trying
• genital itching or thrush
• cuts and wounds taking longer to heal
• blurred vision
• feeling extremely thirsty.

Causes of prediabetes

At the moment, 13.6 million people are at increased risk of type 2 diabetes in the UK. If you’ve been told you have prediabetes, this is a warning sign that you are at high risk of developing type 2 diabetes. The good news is you don’t have it yet, and with the right support up to 50% of cases of type 2 diabetes can be prevented or delayed.

Type 2 diabetes happens because insulin can’t work properly, so your blood sugar levels keep rising. This means more insulin is released. For some people with type 2 diabetes this can eventually tire the pancreas out, meaning their body makes less and less insulin. This can lead to even higher blood sugar levels.

Type 2 diabetes can come on slowly, usually over the age of 40. The signs may not be obvious, or there may be no signs at all, therefore it might be up to 10 years before you find out you have it.

That’s why it’s very important to know the risk factors:

• You’re more at risk if you’re white and over 40 or over 25 if you’re African-Caribbean, Black African, or South Asian.
• You’re two to six times more likely to get type 2 diabetes if you have a parent, brother, sister or child with diabetes.
• Type 2 diabetes is two to four times more likely in people of South Asian descent and African-Caribbean or Black African descent.
• You’re more at risk if you’ve ever had high blood pressure.
• You’re more at risk of type 2 diabetes if you’re carrying extra weight, especially if this weight is around your middle.

You are more at risk of developing type 2 diabetes if some or all of the risk factors apply to you. Our Know Your Risk online tool only takes a couple of minutes to complete. If your results show that you are at high or very high risk, you will need to ask your GP for a blood test.

You could be eligible for a place on the Healthier You: NHS Diabetes Prevention Programme in England.

You may also be eligible for a free NHS Health Check which will check for health conditions including type 2 diabetes.