Confused about diabetes, prediabetes or blood sugar? This plain-English guide from a specialist GP explains what diabetes really is, who gets it, and what to do next.
What nobody tells you about diabetes
Most people have had diabetes for years before they know it.
That is not a scare story. It is just the reality of how diabetes works, and why understanding it early makes such a difference.
This guide covers the essentials. What diabetes actually is, the different types, what prediabetes means, and why getting the right information now matters more than most people realise.
So what exactly is diabetes?
Diabetes is a condition where the level of sugar (glucose) in your blood stays higher than it should.
Normally, your body manages blood sugar automatically. You eat, your blood sugar rises, and your pancreas releases a hormone called insulin. Insulin acts like a key. It unlocks your cells so glucose can enter and be used as energy.
In diabetes, this system breaks down. Either:
- Your body does not produce enough insulin
- Your body produces insulin, but cannot use it properly
- Or both
The result is the same. Blood sugar stays elevated, and over time that causes damage to blood vessels, nerves, kidneys, eyes and the heart.
The different types of diabetes
It is not one condition. There are several distinct types, and the differences matter.
Type 1 diabetes
- An autoimmune condition: the immune system attacks the insulin-producing cells in the pancreas
- The pancreas produces little or no insulin
- Not caused by diet or lifestyle
- Usually diagnosed in childhood or early adulthood, though it can appear at any age
- Managed with insulin. There is no alternative.
Type 2 diabetes
- The most common type, accounting for around 90% of all diabetes cases in the UK
- The body either does not produce enough insulin or the cells become resistant to it
- Strongly linked to lifestyle factors including weight, diet, physical activity and sleep. Genetics also play a significant role.
- Often develops gradually over many years
- Can be managed with lifestyle changes, medication, or both
Prediabetes
- Blood sugar is higher than normal but not yet high enough to be classed as Type 2 diabetes
- No symptoms in most cases. Most people do not know they have it.
- Affects millions of people in the UK
- Importantly, it is reversible with the right changes
Gestational diabetes
- Develops during pregnancy
- Usually resolves after birth, but increases the risk of Type 2 diabetes later in life
LADA (Latent Autoimmune Diabetes in Adults)
- Sometimes called Type 1.5
- Shares features of both Type 1 and Type 2
- Often misdiagnosed as Type 2, which is why specialist review matters
Who gets diabetes?
Type 2 diabetes and prediabetes are far more common than most people realise. In the UK:
- Over 4.3 million people are living with diabetes
- An estimated 850,000 people have Type 2 diabetes and do not know it
- Around 7 million people are living with prediabetes
Risk factors for Type 2 diabetes include:
- Being overweight, particularly around the abdomen
- A family history of Type 2 diabetes
- South Asian, Black African or African Caribbean background
- Age over 40 (or over 25 if from a higher-risk ethnic background)
- Previous gestational diabetes
- High blood pressure
- Poor sleep quality
- A diet high in ultra-processed foods and refined carbohydrates
Having one or more of these does not mean you will develop diabetes. But it does mean it is worth knowing your numbers.
How is diabetes diagnosed?
Diabetes is diagnosed through a blood test. The two main tests are:
HbA1c
- Measures your average blood sugar over the previous 2 to 3 months
- The most commonly used test for diagnosing Type 2 diabetes and prediabetes
- Result given as a percentage or in mmol/mol
Fasting glucose
- Measures blood sugar after you have not eaten for at least 8 hours
What the numbers mean:
- Normal: HbA1c below 42 mmol/mol / Fasting glucose below 5.6 mmol/L
- Prediabetes: HbA1c 42 to 47 mmol/mol / Fasting glucose 5.6 to 6.9 mmol/L
- Diabetes: HbA1c 48 mmol/mol or above / Fasting glucose 7.0 mmol/L or above
One abnormal result is not usually enough to diagnose diabetes. A second confirmatory test is typically needed unless you have clear symptoms.
What symptoms should you look out for?
Type 2 diabetes and prediabetes often have no symptoms at all. That is what makes them easy to miss.
When symptoms do appear, they can include:
- Increased thirst
- Passing urine more frequently, particularly at night
- Unexplained tiredness and low energy
- Blurred vision
- Slow-healing cuts or wounds
- Frequent infections
- Tingling or numbness in hands or feet
If you recognise any of these, particularly if you have known risk factors, it is worth getting a blood test.
Why early action makes a difference
Prediabetes is reversible. Type 2 diabetes, caught early, can be put into remission in many cases. The longer blood sugar remains elevated without intervention, the more quietly it damages the body.
The good news is that even modest changes make a meaningful difference:
- Losing 5 to 10% of body weight if overweight
- Reducing ultra-processed and high-sugar foods
- Moving more, even walking regularly helps
- Improving sleep quality
- Managing stress
These are not cure-alls. And for many people, medication is also needed and nothing to be ashamed of. But the earlier the conversation starts, the more options are available.
A final word
Diabetes does not have to be overwhelming. Understanding what it is, and what it is not, is the first step.
If you have been told your blood sugar is higher than normal, or you simply want to better understand your health, a specialist consultation can help you make sense of your results and build a plan that works for your life.
The Key Points
- Diabetes is a condition where blood sugar stays consistently higher than it should because insulin is not working properly.
- There are several distinct types including type 1, type 2, prediabetes, gestational diabetes, and LADA, and the differences between them matter.
- Type 2 diabetes and prediabetes are extremely common in the UK, and millions of people have them without knowing.
- Diagnosis is through a simple blood test, and if you have risk factors it is worth asking for one.
- Type 2 diabetes and prediabetes often cause no symptoms, which is why waiting for a sign before getting checked can mean missing a long window for action.
- Prediabetes is reversible and type 2 diabetes caught early can be put into remission, so acting sooner gives you the most options.
Author: Dr Imran Mughal, Private Specialist GP
Website: www.imclinic.co.uk
Book a consultation: https://notes.thanksdoc.co.uk/book/clinic/im-clinic
References
Diabetes UK. Diabetes statistics. 2024.
American Diabetes Association. Standards of Medical Care in Diabetes. 2026.
NHS. Type 2 diabetes: symptoms and diagnosis. 2024.
NICE Guideline NG28. Type 2 diabetes in adults: management. 2022 updated 2024.
