Diabetes Explained: Symptoms, Types, Tests and Treatment in the UK

Diabetes is one of the most common long-term health conditions in the UK, but it is also one of the most misunderstood. Some people think diabetes is simply about eating too much sugar. Others assume it only affects older adults, or that symptoms are always obvious. In reality, diabetes is a group of conditions that affect how the body handles glucose, the sugar that circulates in the blood and provides energy for cells.

For some people, diabetes develops quickly and needs urgent treatment. For others, it builds slowly over months or years and may only be found after a blood test. Some people feel tired, thirsty or generally “not right” for a long time before getting checked. Others have no symptoms at all.

This guide explains diabetes in plain English for UK readers. It covers the main types of diabetes, early symptoms, when to seek help, what blood tests mean, how diabetes is treated, and how it connects with weight, blood pressure, cholesterol, kidney health and private healthcare options.

Important: this article is for general information only. It should not replace advice from your GP, diabetes nurse, pharmacist or specialist diabetes team. If you feel seriously unwell, have symptoms of diabetic ketoacidosis, or are worried about a child, seek urgent medical help.

What diabetes actually means

Diabetes means that the level of glucose in your blood is too high. Glucose comes partly from the food you eat, especially carbohydrates, and partly from glucose released by the liver. Your body normally keeps blood glucose within a safe range using hormones, especially insulin.

Insulin acts like a key. It helps glucose move out of the blood and into the body’s cells, where it can be used for energy. Diabetes happens when the body either does not make enough insulin, cannot use insulin properly, or both.

When glucose stays too high for too long, it can damage blood vessels and nerves. This is why diabetes is linked with problems affecting the eyes, kidneys, feet, heart, brain and circulation. The good news is that early diagnosis and good management can greatly reduce the risk of serious complications.

Diabetes is not one single condition. The most common forms are type 1 diabetes, type 2 diabetes and gestational diabetes. Prediabetes is also important because it means blood glucose is higher than normal but not yet in the diabetes range.

Type 1, type 2, gestational diabetes and prediabetes

The different types of diabetes can sound similar, but they have different causes and treatments.

Type 1 diabetes

Type 1 diabetes is an autoimmune condition. This means the immune system mistakenly attacks the insulin-producing cells in the pancreas. As a result, the body makes little or no insulin. People with type 1 diabetes need insulin treatment to survive.

Type 1 diabetes can happen at any age, but it often starts in childhood, adolescence or young adulthood. Symptoms can develop quickly, sometimes over days or weeks. In children, the classic warning signs are often described as the “4 Ts”: toilet, thirsty, tired and thinner.

Type 1 diabetes is not caused by lifestyle, weight or eating too much sugar.

Type 2 diabetes

Type 2 diabetes is much more common than type 1. In type 2 diabetes, the body becomes resistant to insulin, and over time the pancreas may struggle to make enough insulin to keep blood glucose under control.

Type 2 diabetes often develops gradually. Some people have symptoms, but many are diagnosed through routine blood tests. Risk is influenced by age, family history, ethnicity, weight, waist size, activity levels and other health conditions. It is not caused by one food alone, but diet, weight and activity can strongly affect risk and management.

Type 2 diabetes is often managed with lifestyle changes, tablets such as metformin, injectable medicines, insulin, or a combination of treatments.

Gestational diabetes

Gestational diabetes develops during pregnancy. It usually improves after birth, but it increases the future risk of type 2 diabetes. Pregnant women are usually offered screening if they have risk factors, such as a previous large baby, previous gestational diabetes, higher BMI, family history or certain ethnic backgrounds.

Prediabetes

Prediabetes means blood glucose is higher than normal but not high enough for a diagnosis of diabetes. It is sometimes called non-diabetic hyperglycaemia. It matters because it is a warning sign: type 2 diabetes risk is higher, but lifestyle changes and weight loss, where appropriate, can reduce that risk.

If you have been told you have prediabetes, it does not mean type 2 diabetes is inevitable. It means now is the right time to act.

Early symptoms of diabetes

Diabetes symptoms can be subtle, especially in type 2 diabetes. Many people explain them away as stress, poor sleep, ageing, menopause, busy work, dehydration or a minor infection. That is why diabetes can go undiagnosed for some time.

Common symptoms of diabetes include:

peeing more often than usual, especially at night
feeling very thirsty
feeling unusually tired or lacking energy
unexplained weight loss
blurred vision
slow-healing cuts or wounds
recurrent infections, such as thrush, urine infections or skin infections
itching around the genitals
numbness, tingling or burning sensations in the feet or hands

In type 1 diabetes, symptoms can come on quickly and weight loss may be more noticeable. In type 2 diabetes, symptoms may be mild, vague or absent. Some people only discover type 2 diabetes after a health check, an eye test, a urine test, a private blood test or tests for another problem.

Symptoms such as tiredness, thirst, weight change, infections or blurred vision can have many causes. Diabetes is one possible explanation, but it is not the only one. If symptoms are persistent, new or unexplained, it is sensible to speak to a GP and ask whether blood glucose testing is appropriate.

You may also find these related guides useful: Fatigue: Why Am I Always Tired?, Unexplained Weight Loss, Numbness and Tingling and Urine Test Results Explained.

When diabetes symptoms are urgent

Most diabetes checks can start with a routine GP appointment, but some symptoms need urgent medical advice. This is especially important if symptoms are developing quickly, if a child is affected, or if someone appears very unwell.

Seek urgent medical help if you or someone else has symptoms that could suggest diabetic ketoacidosis, also known as DKA. This is a serious complication caused by a severe lack of insulin. It is more common in type 1 diabetes, but it can occasionally happen in other situations too.

Warning signs can include:

extreme thirst and peeing a lot
feeling very tired, drowsy or confused
stomach pain
nausea or vomiting
fast or deep breathing
breath that smells fruity, like pear drops or nail polish remover
blurred vision
signs of dehydration

If someone has diabetes and is vomiting, very drowsy, confused, breathing unusually, or has high blood sugar with ketones, they should get urgent medical advice. If symptoms are severe, call 999 or go to A&E.

Parents should be particularly cautious. A child who is suddenly drinking a lot, peeing a lot, losing weight, wetting the bed after previously being dry, or becoming very tired should be assessed promptly. Do not wait to see if it settles by itself.

For official emergency guidance, see the NHS page on diabetic ketoacidosis.

Who is more likely to develop type 2 diabetes?

Type 2 diabetes is common, and the number of people affected in the UK has increased over time. Diabetes UK estimates that millions of adults are living with diabetes or prediabetes, and NICE notes that around 90% of people with diabetes have type 2 diabetes.

Risk is not about blame. Type 2 diabetes develops because of a mix of biology, environment, genetics and lifestyle. Some risk factors can be changed, while others cannot.

You may be at higher risk of type 2 diabetes if you:

are over 40, or over 25 if you are from a higher-risk ethnic background
have a parent, brother or sister with type 2 diabetes
are living with overweight or obesity, especially around the waist
have high blood pressure
have high cholesterol or other cardiovascular risk factors
have had gestational diabetes
have polycystic ovary syndrome, especially if weight gain or insulin resistance is present
are physically inactive
have had blood tests showing prediabetes or raised HbA1c

People of South Asian, Black African, African-Caribbean, Chinese and some Middle Eastern backgrounds may develop type 2 diabetes at a younger age and at a lower BMI than white European populations. This is one reason why risk assessment should be individual rather than based on weight alone.

Diabetes also overlaps with other long-term risk areas. If you are looking at your wider health, you may find it useful to read Cardiovascular Risk: The Complete Guide to Heart Attack and Stroke Prevention, High Blood Pressure: Symptoms, Causes and Treatment and High Cholesterol: Causes, Treatment and How to Lower It.

How diabetes is diagnosed in the UK

Diabetes is diagnosed with blood tests. Symptoms can suggest diabetes, but a blood test is needed to confirm it.

The most common test is HbA1c. This shows your average blood glucose level over the previous two to three months. It is useful because it does not usually require fasting and gives a longer-term picture than a single glucose reading.

Other tests may include fasting blood glucose, random blood glucose or an oral glucose tolerance test. In pregnancy, gestational diabetes is usually checked with an oral glucose tolerance test rather than relying only on HbA1c.

Typical diabetes-related blood tests include:

HbA1c: gives an average blood sugar picture over around two to three months
Fasting blood glucose: measures blood glucose after not eating for a set period
Random blood glucose: measures glucose at any time of day
Oral glucose tolerance test: checks how the body handles glucose after a glucose drink
Kidney function tests: check how well the kidneys are working
Urine albumin-to-creatinine ratio: looks for early signs of kidney strain
Cholesterol tests: assess cardiovascular risk
Liver function tests: may be relevant because type 2 diabetes can overlap with fatty liver disease

HbA1c results are usually reported in mmol/mol in the UK. A result in the diabetes range should be interpreted by a clinician, especially if there are symptoms, pregnancy, anaemia, recent blood loss, kidney disease, certain haemoglobin conditions, or suspected type 1 diabetes. In some situations, HbA1c may not be the best diagnostic test.

If you want a fuller explanation of test results, read HbA1c and Blood Sugar Results Explained, How to Understand Blood Test Results, Kidney Blood Test Results Explained and Cholesterol Test Results Explained.

What happens after a diabetes diagnosis?

A diabetes diagnosis can feel overwhelming, but it is not the end of the story. The aim is to understand what type of diabetes you have, bring blood glucose into a safer range, reduce future risks, and help you live well day to day.

After diagnosis, your GP practice or diabetes team may discuss:

your HbA1c level and personal blood sugar target
whether symptoms suggest type 1, type 2 or another form of diabetes
diet, activity, weight and lifestyle changes
whether medication is needed
blood pressure and cholesterol
kidney checks and urine testing
foot checks
eye screening
smoking, alcohol and cardiovascular risk
support with education, emotional wellbeing and long-term management

People with type 1 diabetes should be referred urgently to a specialist diabetes team and started on insulin. People with type 2 diabetes are usually managed initially through GP care, practice nurses, pharmacists and diabetes education, with specialist referral if needed.

One of the most important things to understand is that diabetes care is not only about sugar. Blood pressure, cholesterol, kidney health, smoking, weight, sleep, medication safety and foot care all matter. A person with “reasonable” blood sugar but very high blood pressure may still be at high risk. A person with raised HbA1c but improving weight, diet and medication adherence may be moving in the right direction.

NICE guidance on type 2 diabetes in adults focuses not only on blood glucose, but also education, dietary advice, cardiovascular risk and long-term complications.

Treatment options for diabetes

Diabetes treatment depends on the type of diabetes, blood glucose levels, symptoms, other medical conditions, personal preferences and risk of complications.

Lifestyle and education

Lifestyle changes are central to type 2 diabetes management and can also support people with type 1 diabetes. This does not mean “just try harder”. It means building realistic habits that improve blood glucose, weight, blood pressure, cholesterol and energy levels.

Helpful areas often include:

understanding carbohydrates and portion sizes
choosing more high-fibre foods such as vegetables, beans, lentils and wholegrains
reducing sugary drinks and frequent high-sugar snacks
adding regular activity, even if starting with short walks
losing weight if appropriate and realistic
improving sleep and managing stress
stopping smoking
reducing excess alcohol

Metformin and other tablets

Metformin is often the first medicine used for type 2 diabetes. It helps reduce glucose production by the liver and improves how the body responds to insulin. Common side effects include nausea, diarrhoea, stomach upset and appetite changes, especially when starting treatment. Many people tolerate it better when it is taken with food or changed to a slow-release version, but medication decisions should always be made with a clinician.

Other diabetes tablets may be used depending on HbA1c, weight, kidney function, heart disease risk, side effects, cost and individual goals. These can include SGLT2 inhibitors, DPP-4 inhibitors, sulfonylureas and other medicines.

GLP-1 medicines and weight loss injections

GLP-1 receptor agonists and related medicines can help some people with type 2 diabetes by improving blood glucose control, supporting weight loss and reducing appetite. Some medicines in this wider area are also used for weight management under specific rules.

This is an area where people can easily get confused because brand names, licensing, NHS access, private prescribing and weight loss marketing often overlap. For more detail, read GLP-1: What It Actually Does, Weight Loss Injections in the UK, Ozempic for Weight Loss in the UK, Mounjaro vs Wegovy and How to Get Mounjaro on the NHS.

Insulin

People with type 1 diabetes need insulin. Some people with type 2 diabetes also need insulin, especially if blood glucose remains high despite other treatment, if symptoms are significant, during pregnancy, or if the pancreas is no longer producing enough insulin.

Insulin can be life-changing, but it requires education. People using insulin need to understand dose timing, hypoglycaemia, sick-day rules, driving rules where relevant, injection technique and blood glucose monitoring.

Blood pressure, cholesterol and kidney protection

Diabetes treatment often includes medicines that are not “diabetes medicines” in the narrow sense. Blood pressure tablets, statins and kidney-protective medicines may be recommended because diabetes increases the risk of heart attack, stroke, kidney disease and circulation problems.

This is why diabetes appointments often include blood pressure checks, cholesterol tests and urine tests. These are not extras; they are part of preventing complications.

Living with diabetes day to day

Living with diabetes is not about being perfect. It is about building repeatable habits, understanding your own body and knowing when to ask for support.

Food is often the first thing people worry about. A diabetes-friendly diet does not usually mean cutting out all carbohydrates. It means choosing the type, amount and timing of carbohydrates more carefully, while also paying attention to fibre, protein, fats, portion sizes and overall calorie intake where weight loss is a goal.

For many people with type 2 diabetes, practical changes make the biggest difference:

swapping sugary drinks for water, tea, coffee or sugar-free alternatives
building meals around vegetables, protein and high-fibre carbohydrates
reducing large portions of white bread, chips, white rice, pasta, pastries and sweets
walking after meals where possible
planning snacks instead of grazing
keeping alcohol within recommended limits
checking food labels for sugar, carbohydrate and portion size

Exercise helps the body use glucose more effectively. It does not have to mean the gym. Brisk walking, cycling, swimming, gardening, dancing, resistance bands or short strength exercises can all help. The most useful activity is the one you can keep doing.

Home blood glucose monitoring depends on your situation. People with type 1 diabetes and people using insulin usually need regular monitoring. Some people with type 2 diabetes benefit from finger-prick testing or continuous glucose monitoring, but not everyone needs it. If you are not on insulin, ask your GP or diabetes nurse whether home testing is useful for you and how to interpret the numbers.

Diabetes can also affect emotional wellbeing. Some people feel guilt, fear, frustration or burnout. That is normal. If diabetes management feels overwhelming, ask for help. Support from a diabetes nurse, dietitian, pharmacist, GP, structured education course or mental health professional can make a real difference.

Can type 2 diabetes be reversed?

Some people with type 2 diabetes can achieve remission. Remission usually means blood glucose has returned below the diabetes range without glucose-lowering medication for a sustained period. It does not mean the body is permanently “cured” or that diabetes can never return.

Weight loss can be particularly powerful for people whose type 2 diabetes is linked with excess weight around the liver and pancreas. For some people, significant weight loss can improve insulin sensitivity and allow the pancreas to work better. This may be achieved through diet changes, structured weight management programmes, medication, or in some cases weight loss surgery.

However, remission is not possible for everyone. It depends on factors such as how long someone has had diabetes, how much insulin-producing capacity remains, age, genetics, weight pattern, other health conditions and treatment history. Even if remission is not achieved, improving HbA1c, blood pressure, cholesterol, fitness and weight can still greatly reduce risk.

Be cautious with anyone promising a guaranteed diabetes cure. A good plan is medically supervised, realistic, nutritionally safe and monitored with proper blood tests.

If weight is part of your diabetes picture, these guides may help: Weight Loss Surgery in the UK, Can You Get Weight Loss Treatment on the NHS? and Are Online Weight Loss Jabs Safe?.

NHS care, private diabetes checks and health insurance

Most diabetes diagnosis and ongoing care in the UK starts with the NHS. Your GP practice can arrange blood tests, review symptoms, prescribe medication, refer to specialist services and help monitor long-term risk. NHS diabetes care may include annual reviews, retinal screening, foot checks, kidney checks, blood pressure checks and medication reviews.

Private healthcare can sometimes be useful if you want faster access to a GP appointment, additional blood tests, a second opinion, a dietitian, a private endocrinologist, a weight management clinic or a more detailed health check. However, private care should not replace urgent NHS care, and it should ideally be shared with your NHS GP so records, prescriptions and safety checks stay joined up.

Private health checks often include HbA1c, cholesterol, liver function, kidney function and sometimes urine tests. These can be useful, but abnormal results need proper interpretation. A blood test number without clinical context can cause unnecessary worry or false reassurance.

If you are considering private tests or consultations, read Private GP Services in the UK: Costs, Private Health Check Cost in the UK, What to Do After Abnormal Private Blood Test Results and NHS vs Private Healthcare.

Health insurance can be more complicated. Diabetes may be classed as a pre-existing condition if it was present before the policy started. Some policies may cover new complications or specialist consultations depending on underwriting, exclusions and policy terms, while routine long-term management may not be covered. Always check the wording carefully before assuming diabetes care is included.

For more on insurance, see What Is Private Medical Insurance?, Pre-Existing Conditions and Health Insurance and What Does Private Health Insurance Actually Cover?.

How to reduce your risk and protect your future health

Whether you have prediabetes, type 2 diabetes, a family history of diabetes or no diagnosis at all, prevention and risk reduction are worth taking seriously.

The most effective steps are often simple, but not always easy:

know your risk, especially if diabetes runs in your family
ask about HbA1c testing if you have symptoms or risk factors
aim for gradual, sustainable weight loss if advised
move more often during the day, not only during formal exercise
reduce sugary drinks and frequent ultra-processed snacks
eat more fibre-rich foods
check blood pressure and cholesterol
attend diabetes reviews and screening appointments
look after your feet and report wounds, numbness or infections
do not ignore changes in vision
take prescribed medication consistently unless told otherwise by a clinician

Diabetes care is a long-term relationship with your body. The aim is not to make every meal perfect or every reading ideal. The aim is to notice patterns, make better decisions more often, and get support before small problems become serious ones.

If you are worried about symptoms, start with a GP appointment and a blood test. If you already have diabetes and feel your treatment is not working, ask for a review. If you have prediabetes, treat it as a chance to act early. Diabetes is serious, but it is also manageable — and for many people, the biggest improvements start with understanding what is actually going on.

Frequently asked questions

What are the first signs of diabetes?

Common early signs include peeing more often, feeling very thirsty, tiredness, blurred vision, unexplained weight loss, slow-healing cuts and recurrent infections such as thrush or urine infections. Type 1 diabetes symptoms often develop quickly, while type 2 symptoms may be mild or absent.

Can you have diabetes without symptoms?

Yes. Type 2 diabetes can be present for months or years without obvious symptoms. Some people are diagnosed after a routine HbA1c test, health check, eye test, urine test or private blood test.

Is diabetes caused by eating too much sugar?

Diabetes is not caused by sugar alone. Type 1 diabetes is autoimmune and not caused by diet. Type 2 diabetes is influenced by several factors, including genetics, age, ethnicity, weight, waist size, activity levels and overall diet. Sugary drinks and frequent high-calorie foods can contribute to weight gain and higher risk, but they are only part of the picture.

What is the difference between type 1 and type 2 diabetes?

Type 1 diabetes happens when the immune system destroys insulin-producing cells, so insulin treatment is needed. Type 2 diabetes usually involves insulin resistance and gradually reduced insulin production. Type 2 is more common and is often linked with age, family history, weight and lifestyle factors, although it can affect younger adults too.

What blood test checks for diabetes?

The most common test is HbA1c, which shows average blood glucose over the previous two to three months. Other tests include fasting blood glucose, random blood glucose and oral glucose tolerance testing. The best test depends on symptoms, pregnancy, age, medical history and whether type 1 diabetes is suspected.

What does prediabetes mean?

Prediabetes means blood glucose is higher than normal but not high enough for a diabetes diagnosis. It increases the risk of type 2 diabetes, but lifestyle changes, weight loss where appropriate and regular monitoring can reduce that risk.

Can type 2 diabetes go into remission?

Yes, some people with type 2 diabetes can achieve remission, especially after significant weight loss. Remission usually means blood glucose returns below the diabetes range without glucose-lowering medication for a sustained period. It does not mean diabetes can never return, so ongoing monitoring is still important.

Do all people with diabetes need insulin?

No. People with type 1 diabetes need insulin. Some people with type 2 diabetes need insulin, but many are managed with lifestyle changes, tablets, injectable non-insulin medicines or a combination of treatments.

Should I buy a home blood glucose monitor?

It depends. People using insulin usually need regular glucose monitoring. Some people with type 2 diabetes may benefit from home testing, but others may not need it routinely. Ask your GP, diabetes nurse or pharmacist whether testing is useful for your situation and how often to test.

When should I seek urgent help for possible diabetes?

Seek urgent help if symptoms are severe or developing quickly, especially in a child. Warning signs include vomiting, stomach pain, deep or fast breathing, confusion, extreme drowsiness, dehydration, fruity-smelling breath, or symptoms of high blood sugar with ketones. These may suggest diabetic ketoacidosis and need urgent medical assessment.

Can private healthcare help with diabetes?

Private healthcare may help with faster appointments, blood tests, dietitian support, endocrinology consultations or weight management services. However, diabetes is usually a long-term condition that needs joined-up care, so private results and treatment plans should be shared with your NHS GP where possible.

Does health insurance cover diabetes?

It depends on the policy. If diabetes was present before the policy started, it may be treated as a pre-existing condition and excluded. Some policies may cover certain complications, specialist consultations or new symptoms depending on the terms. Always check the policy wording and exclusions carefully.