Understanding Diabetes: From Symptoms to Management
01/06/2026
Diabetes affects millions in the UK, and many more are living with prediabetes without even knowing it.
Summary
Whether you have recently been diagnosed, are concerned about symptoms, or are supporting someone close to you, the sections on diabetes below walk through what diabetes is and how insulin works, the different types including Type 1, Type 2, and gestational diabetes, how the condition is diagnosed and monitored, the medications and technologies available today, and what the future of diabetes care looks like in the UK.
What is Diabetes?
Diabetes is a condition where the level of sugar (glucose) in your blood becomes too high. It happens when the body either cannot produce enough insulin, or when the insulin it does produce no longer works properly.
Insulin is a hormone made by the pancreas. Its job is to move glucose from your bloodstream into your cells, where it is used for energy.
When that process breaks down, glucose builds up in the blood instead, which over time can cause serious health problems.
According to Diabetes UK, around 4.4 million people in the UK are currently diagnosed with diabetes, with an estimated 850,000 more living with undiagnosed Type 2 diabetes.
There are several types of diabetes. The most common are:
• Type 1: an autoimmune condition where the immune system destroys insulin-producing cells in the pancreas.
• Type 2: the body does not make enough, or becomes resistant to insulin; accounts for around 90% of all diabetes cases in the UK.
• Gestational: high blood sugar that develops during pregnancy and usually resolves after birth.
• Other types: including MODY (maturity-onset diabetes of the young) and secondary diabetes caused by other conditions.
Each type is covered in more depth further down this page. For a broad overview of all types, the NHS diabetes guide is a useful starting point.
Diabetes Prevention
Type 2 diabetes is not inevitable, even for people at higher risk. Lifestyle changes can significantly reduce the chance of developing the condition, particularly for those with prediabetes.
NHS England's Diabetes Prevention Programme offers a free, referral-based service to help people at high risk make sustainable changes to their diet, activity levels, and weight. Evidence from the programme shows it can reduce the risk of developing Type 2 diabetes by around 20%.
Key modifiable risk factors for Type 2 diabetes include:
• Carrying excess weight, particularly around the abdomen
• Low levels of physical activity
• A diet high in processed food and refined carbohydrates
• Smoking
• A family history of Type 2 diabetes
Taking action on these factors does not require a clinical diagnosis first. Anyone concerned about their risk can ask their GP for a check or use Diabetes UK's Know Your Risk tool to get an initial assessment.
Symptoms of Diabetes
Many people with Type 2 diabetes have no obvious symptoms for years. When symptoms do appear, they tend to develop gradually. Type 1 symptoms come on more quickly, sometimes over days or weeks.
Common symptoms of diabetes include:
• Increased thirst and a dry mouth
• Needing to urinate more frequently, especially at night
• Fatigue and low energy
• Blurred vision
• Cuts or wounds that heal slowly
• Unexplained weight loss (more common in Type 1)
• Recurring infections, such as thrush
If you recognise several of these symptoms, the NHS recommends booking an appointment with your GP rather than waiting. A straightforward blood test is usually all that is needed to investigate further.
Blood sugar levels
Blood sugar is measured in millimoles per litre (mmol/L) or, for the HbA1c test, in millimoles per mole (mmol/mol). Understanding what the numbers mean helps make sense of a diagnosis or monitoring result.
The table below shows NICE reference ranges:
| Test | Normal | Prediabetes | Diabetes |
|---|---|---|---|
| Fasting glucose (mmol/L) | Below 6.0 | 6.0 to 6.9 | 7.0 and above |
| HbA1c (mmol/mol) | Below 42 | 42 to 47 | 48 and above |
These ranges are a guide. A GP will interpret results alongside other factors such as symptoms and medical history.
When to see a doctor
You should speak to your GP if you are experiencing multiple diabetes symptoms, if a blood test has returned results in the prediabetic range, or if you have risk factors such as a family history of Type 2, obesity, or a previous gestational diabetes diagnosis.
The NHS diabetes testing page sets out who is eligible for a diabetes check and what to expect.
Diagnosing Diabetes
Diagnosis is based on a blood test. In most cases, a GP will use one of two tests: the HbA1c test or a fasting plasma glucose test.
The HbA1c test
The HbA1c test measures your average blood sugar level over the past two to three months. Because it reflects a longer-term picture rather than a single moment in time, it is the standard diagnostic tool for Type 2 diabetes in the UK.
A result of 48 mmol/mol or above on two separate tests usually confirms a Type 2 diagnosis. A result between 42 and 47 mmol/mol indicates prediabetes. The same test is used to monitor how well diabetes is being managed over time, making it central not just to diagnosis but to ongoing care.
NHS guidance on the HbA1c test explains the process in full.
Other diagnostic tests
A fasting plasma glucose test measures blood sugar after you have not eaten for at least eight hours. A result of 7.0 mmol/L or above on two occasions indicates diabetes.
A random glucose test, taken at any time of day, may also be used if symptoms are severe.
Your GP will advise which test is most appropriate based on your situation.
Prediabetes
Prediabetes means your blood sugar is higher than normal but not yet high enough to meet the threshold for a Type 2 diagnosis. It is not a condition in itself, but it is a meaningful signal.
The crucial thing to understand is that prediabetes does not mean Type 2 diabetes is inevitable. Diabetes UK reports that around 5 to 10% of people with prediabetes progress to Type 2 each year, but that lifestyle interventions can halt or reverse that progression in a significant number of cases.
Most people with prediabetes have no symptoms at all, which is why it often goes undetected without a blood test.
High blood sugar symptoms
When blood sugar does rise to symptomatic levels, the most common signs are increased thirst, frequent urination, fatigue, and headaches.
These can be easy to attribute to other causes, which is one reason many people with prediabetes remain unaware of their raised glucose levels.
For those already diagnosed with prediabetes, the NHS Diabetes Prevention Programme provides structured support.
Type 1 Diabetes
Type 1 diabetes is an autoimmune condition.
The immune system mistakenly attacks and destroys the beta cells in the pancreas that produce insulin, meaning the body can no longer make insulin at all.
It is not caused by diet or lifestyle. It can develop at any age, though it is most commonly diagnosed in children and young adults. Around 8% to 10% of people with diabetes in the UK have Type 1, according to Diabetes UK.
Because the body produces no insulin, insulin therapy is essential for everyone with Type 1.
Management today increasingly involves continuous glucose monitors (CGMs) and hybrid closed-loop insulin pump systems, which automatically adjust insulin delivery based on real-time glucose readings.
These technologies have significantly reduced the burden of daily management for many people living with Type 1.
Type 2 Diabetes
Type 2 is the most common form of diabetes in the UK, accounting for approximately 90% of all cases. It develops when the body becomes resistant to insulin, or when the pancreas cannot produce enough insulin to keep blood sugar at a healthy level.
Risk increases with age, weight, and inactivity, though Type 2 is being diagnosed in younger people at increasing rates. NICE updated its Type 2 diabetes treatment guidelines in 2025, in what the organisation described as the most significant shake-up in Type 2 care in a decade.
The updated guidance places greater emphasis on earlier intervention, remission, and the use of SGLT-2 inhibitors and GLP-1 receptor agonists as frontline treatments.
Can type 2 diabetes be reversed?
The clinically accepted term is remission rather than reversal, and evidence shows it is achievable for some people.
Remission means blood sugar levels return to the normal range without the need for diabetes medication.
The NHS Type 2 Diabetes Path to Remission Programme is a structured, low-calorie dietary programme available through the NHS.
The programme draws on evidence from the DiRECT trial, a Diabetes UK-funded study that found 46% of participants who received the weight management programme were in remission after one year.
Remission is not guaranteed and requires sustained lifestyle change, but it is a realistic goal for a significant number of people with Type 2 diabetes.
Type 1 vs Type 2 Diabetes: Key Differences
| Diabetes | Type 1 | Type 2 |
|---|---|---|
| Cause | Autoimmune - immune system attacks insulin-producing cells | Insulin resistance or insufficient insulin production |
| Who it affects | Any age; often diagnosed in childhood or young adulthood | More common in adults over 40, increasingly seen in younger people |
| Onset | Symptoms develop quickly | Symptoms develop slowly; often unnoticed for years |
| Insulin dependency | Always required | Not always required |
| Can it go into remission? | No | Yes, for some people |
| Main treatments | Insulin therapy, CGM, diet | Lifestyle changes, medication, monitoring |
Gestational Diabetes
Gestational diabetes is high blood sugar that develops during pregnancy.
It usually resolves after birth, but it requires careful management during pregnancy to protect both the mother and baby.
The NHS estimates that gestational diabetes affects up to 1 in 20 pregnancies in the UK.
Risk is higher for those who are overweight, have a family history of Type 2 diabetes, or have had gestational diabetes before.
All pregnant women are offered a glucose tolerance test between 24 and 28 weeks.
Management typically involves dietary changes, regular blood sugar monitoring, and in some cases insulin or metformin.
Women who have had gestational diabetes have a higher lifetime risk of developing Type 2 diabetes and are advised to have annual blood sugar checks.
Managing and Monitoring Diabetes
Managing diabetes means keeping blood sugar within a healthy range, which involves a combination of lifestyle choices, monitoring, and in many cases medication.
Treatment differs by type and by individual, and a GP or diabetes specialist will guide the right approach for each person.
Insulin
Insulin therapy is essential for Type 1 diabetes and is used by some people with Type 2 when other treatments are no longer sufficient. It is delivered by injection or through an insulin pump.
There are several types of insulin, including fast-acting insulin taken at mealtimes and long-acting insulin that provides background coverage throughout the day.
Smart insulin pens can record the timing and dose of each injection and sync with an app, making it easier to share accurate data with a care team.
GLP-1 Medications: Mounjaro and Ozempic
GLP-1 receptor agonists are a type of injectable medication that mimic a hormone the body produces naturally.
They work by stimulating insulin release, reducing glucagon production, and slowing the rate at which the stomach empties, all of which helps lower blood sugar. Many people also experience weight loss as a result of the treatment.
Mounjaro (tirzepatide) and Ozempic (semaglutide) are two GLP-1 medications currently approved for use in the UK.
NICE recommended tirzepatide (Mounjaro) for weight management, and NHS England began rolling out access from March 2025 for eligible patients. Eligibility criteria are set nationally and assessed by a GP or specialist.
An estimated 1.6 million UK adults used GLP-1 medications in the year to early 2025.
These are prescription medications. Eligibility and suitability are determined by a GP or prescriber.
Diabetes Essentials
GLP-1 medication and blood glucose monitoring from Ozempic and GlucoRx.
-
£102.50£123.00 inc VAT
-
J1402Order from supplier within 7 working days.£102.99£123.59 inc VAT
-
£17.00£20.40 inc VAT
Diabetes Diet
Food choices have a direct effect on blood sugar levels. Different foods raise blood sugar at different speeds depending on their carbohydrate content and how quickly those carbohydrates are digested.
Practical steps supported by Diabetes UK's dietary guidance include:
• Choosing wholegrain carbohydrates over refined ones, which raise blood sugar more slowly.
• Including protein and healthy fats at mealtimes to slow glucose absorption.
• Reducing portion sizes of starchy foods such as bread, pasta, and rice.
• Limiting ultra-processed foods and added sugars.
• Eating at consistent times to support stable blood sugar levels.
Diet is not about eliminating foods entirely. The NHS Eatwell Guide provides a foundation for balanced eating that is relevant for people managing diabetes as well as those looking to reduce their risk.
Carbohydrate counting
Carbohydrates have the most direct impact on blood sugar of any food group.
Carbohydrate counting is a technique used particularly by people with Type 1 diabetes to match insulin doses to the amount of carbohydrate in a meal.
For people with Type 2, it supports better portion awareness and more predictable blood sugar levels. A dietitian can provide personalised carbohydrate targets.
Diabetes Technology
Technology has changed what day-to-day diabetes management looks like. Devices that once required hospital visits are now wearable, connected, and increasingly accessible on the NHS.
Blood glucose monitors
A blood glucose monitor measures the glucose level in a small blood sample taken by a finger-prick test.
Results are available in seconds and allow people to see how food, activity, stress, and medication are affecting their blood sugar in real time.
GlucoRx offers a range of monitors designed for accuracy, ease of use, and value.
The GlucoRx range is suitable for NHS clinical settings and home use, with devices including the GlucoRx HCT, which tests glucose, cholesterol, and haemoglobin from a single drop of blood.
Continuous glucose monitors (CGM)
A CGM is a small sensor worn on the skin that tracks blood sugar continuously, sending readings to a smartphone or dedicated reader without the need for repeated finger pricks.
Readings update every few minutes and can be shared with clinicians or carers in real time.
NHS guidance on CGM eligibility has expanded in recent years.
As of 2024, CGM is available on the NHS for all people with Type 1 diabetes and for some people with Type 2 who use insulin.
Flash glucose monitors, such as the FreeStyle Libre, scan the sensor on demand rather than transmitting continuously. A distinction worth understanding when comparing options.
Smart insulin pens and connected devices
Connected insulin pens record the dose and timing of each injection automatically and sync the data to an app.
This removes the burden of manual logging and allows clinicians to review accurate injection records during appointments.
Several manufacturers now offer connected pen systems that integrate with CGM apps for a unified view of glucose and dosing data.
Diabetes Complications
Many complications of diabetes are preventable with consistent blood sugar management, though they remain a significant risk for those whose diabetes is poorly controlled over time.
Key complications include:
• Cardiovascular disease: people with diabetes are two to four times more likely to develop heart disease, according to the British Heart Foundation.
• Nephropathy: a significant proportion of people with diabetes develop some degree of kidney damage over time.
• Retinopathy: damage to the blood vessels in the eye; the leading cause of preventable blindness in working-age adults in the UK.
• Neuropathy: nerve damage that most often affects the feet and legs, causing numbness, tingling, or pain.
• Foot problems: reduced circulation and nerve damage can cause foot ulcers that are slow to heal.
Regular diabetes check-ups, including annual eye screening and foot examinations, are available through the NHS and are the most reliable way to catch complications before they progress.
The Future of Diabetes Management
This is a significant moment in UK diabetes care.
Remission is achievable, technology is advancing, and national policy is shifting in a way that may change how millions of people are diagnosed and treated.
Diabetes and the NHS 10-year plan
The NHS 10-Year Health Plan, published in July 2025, places prevention at the centre of NHS strategy, with diabetes identified as a key target condition.
The plan expands access to diabetes prevention programmes and increases investment in early diagnosis.
In May 2025, Diabetes UK presented its 10-Year Vision for Diabetes Prevention, Care and Treatment to the House of Commons, calling for broader CGM access, expanded remission pathways, and improved support for people living with Type 1.
Alongside this, NICE's 2025 updated Type 2 guidelines represent the most substantive shift in treatment recommendations in a decade, moving SGLT-2 inhibitors to first-line treatment and expanding GLP-1 prescribing criteria.
Precision medicine and personalised treatment
Research funded by UK Research and Innovation (UKRI) published in early 2025 is exploring how genetic and metabolic data can be used to personalise diabetes treatment, moving away from a one-size-fits-all approach.
The goal is to identify which interventions will be most effective for an individual before treatment begins, reducing trial and error and improving outcomes.
Diabetes Frequently Asked Questions
Is diabetes genetic?
Genetics plays a role in both Type 1 and Type 2 diabetes, but it is not the only factor. Having a parent or sibling with Type 2 diabetes increases your risk, but lifestyle factors such as weight and physical activity are also significant. Type 1 has a weaker genetic link but is still influenced by family history.
What is diabetes mellitus?
Diabetes mellitus is the clinical name for the condition most people refer to simply as diabetes. It covers Type 1, Type 2, gestational, and several rarer forms. The term distinguishes it from diabetes insipidus, which is a different and unrelated condition.
What is diabetes insipidus?
Diabetes insipidus is not related to blood sugar. It is caused by problems with the kidneys or the pituitary gland that affect how the body regulates water, leading to excessive thirst and urination. Despite the shared name, it has no connection to diabetes mellitus.
How do you test for diabetes at home without a machine?
There is no reliable way to test for diabetes at home without a blood glucose monitor or a clinical blood test. If you are concerned about symptoms, the most reliable step is to contact your GP and ask for an HbA1c or fasting glucose test. The NHS diabetes testing page explains what to expect.
What is a measure of glucose control?
The HbA1c test is the standard measure of glucose control. It reflects average blood sugar over the past two to three months by measuring the percentage of haemoglobin coated with glucose. It is used both to diagnose diabetes and to assess how well it is being managed over time.
What should people with diabetes avoid eating?
No single food needs to be completely avoided, but Diabetes UK recommends limiting sugary drinks, refined white carbohydrates, ultra-processed snacks, and foods high in saturated fat. Portion sizes and meal timing matter as much as food choice.
What is the difference between Type 1 and Type 2 diabetes?
Type 1 is an autoimmune condition where the pancreas produces no insulin. Type 2 involves insulin resistance or insufficient insulin production. Type 1 always requires insulin therapy; Type 2 is often managed through lifestyle changes and medication, though some people do require insulin.
What is an HbA1c test?
An HbA1c test is a blood test that measures your average blood sugar level over the past two to three months. A result of 48 mmol/mol or above on two separate occasions usually indicates Type 2 diabetes. The NHS HbA1c page provides full guidance on what to expect.
Can you reverse Type 2 diabetes?
The preferred term is remission rather than reversal. Remission means blood sugar levels return to the normal range without medication. The NHS Type 2 Diabetes Path to Remission Programme supports this goal through a structured dietary approach, and the DiRECT trial showed 46% of participants achieved remission after one year with significant weight loss.
What is Mounjaro used for?
Mounjaro (tirzepatide) is a GLP-1 and GIP receptor agonist approved for the treatment of Type 2 diabetes and, from March 2025, for weight management on the NHS. It works by stimulating insulin release and reducing appetite. It is a prescription medication; NICE guidance sets out the criteria for NHS eligibility.
UK Diabetes Support
The following organisations provide trusted information and support for people living with diabetes in the UK:
• NHS Diabetes: symptoms, diagnosis, treatment pathways, and when to see a GP.
• Diabetes UK: the UK's leading diabetes charity; information, research, helpline, and community forums.
• NICE Diabetes Guidelines: clinical guidance for healthcare professionals and patients on diagnosis and treatment.
• GOV.UK Diabetes Statistics: UK prevalence data and public health information.
• NHS Diabetes Prevention Programme: free, referral-based programme to reduce the risk of Type 2 diabetes.
If you’re a healthcare professional, our Glucose Testing range has essential tools for the diagnosis and monitoring of diabetic symptoms in patients.
Disclaimer: The information on this page is intended for general educational purposes only. It does not constitute medical advice and should not be used as a substitute for professional medical guidance. If you are experiencing symptoms, have received a diabetes-related test result, or have questions about your health, please consult a qualified healthcare professional. In an emergency, call 999 or go to your nearest A&E.