Type 2 Diabetes: The Complete Guide to Diagnosis, Treatment and Living Well

More than 500 million adults worldwide live with diabetes, and most of them have type 2. It is a serious condition, but it is also one where the choices you make every day genuinely change what happens next. This guide brings everything together in one place.

Imagine a routine blood test at work showing an HbA1c of 58. You feel fine, you are busy, and diabetes is something you associated with older relatives. Suddenly you are being told about tablets, diets, eye checks and foot care. Where do you even start? You start here.

What type 2 diabetes is

Type 2 diabetes is a long-term condition in which the level of glucose (sugar) in the blood is too high. Glucose comes from the food we eat and is the body’s main fuel. Insulin, a hormone made by the pancreas, acts like a key that lets glucose move from the blood into the cells where it is used for energy.,In type 2 diabetes, two problems usually develop together. First, the body’s cells stop responding properly to insulin, which is called insulin resistance. Second, the pancreas gradually becomes less able to make enough insulin to overcome that resistance. The result is that glucose builds up in the bloodstream.,Over many years, high blood glucose damages blood vessels and nerves throughout the body. That is why diabetes affects the heart, kidneys, eyes, feet and much more. The good news is that keeping glucose, blood pressure and cholesterol in a healthy range dramatically reduces these risks.

How type 2 differs from type 1

Type 1 diabetes is an autoimmune condition in which the immune system destroys the insulin-producing cells of the pancreas. People with type 1 need insulin from diagnosis, and it often starts in childhood or young adulthood, though it can occur at any age.,Type 2 diabetes is far more common, usually develops gradually in adults, and is strongly linked to weight, inactivity, genetics and age. It is increasingly seen in younger people and even children as obesity rises. Many people with type 2 diabetes are treated with lifestyle changes and tablets at first, though some eventually need insulin.,There are other types too, including gestational diabetes in pregnancy and rarer genetic forms. If your diagnosis does not seem to fit, for example if you are young and slim, ask whether further tests are needed.

Who is at risk

• Being overweight, especially carrying weight around the waist
• Being physically inactive
• Having a parent, brother or sister with type 2 diabetes
• Age: risk rises from about 40, and earlier in some ethnic groups
• People of South Asian, African, African Caribbean, Middle Eastern and some other backgrounds, who tend to develop diabetes at a younger age and at a lower weight
• A history of gestational diabetes
• Polycystic ovary syndrome (PCOS)
• High blood pressure or abnormal cholesterol
• Long-term use of some medicines, such as steroids or some antipsychotics
• Prediabetes: blood glucose that is raised but not yet in the diabetes range

Symptoms to look out for

Many people have no symptoms at all, which is why type 2 diabetes is often found on routine blood tests. Others notice symptoms that build slowly and are easy to dismiss.,Common symptoms include feeling very thirsty, passing urine more often, especially at night, feeling tired, losing weight without trying, blurred vision, itching around the genitals or repeated thrush, and cuts or wounds that take a long time to heal. Some people are diagnosed only when they develop a complication, such as a foot ulcer or eye changes, which is why screening matters.

How diabetes is diagnosed

Type 2 diabetes is usually diagnosed with a blood test. The most common is HbA1c, which reflects your average blood glucose over the past two to three months. Other tests include a fasting plasma glucose test and an oral glucose tolerance test.,According to World Health Organization criteria, diabetes is generally diagnosed with an HbA1c of 48 mmol/mol (6.5%) or above, a fasting glucose of 7.0 mmol/L (126 mg/dL) or above, or a two-hour glucose of 11.1 mmol/L (200 mg/dL) or above on a glucose tolerance test. If you have no symptoms, the test is usually repeated to confirm. An HbA1c between 42 and 47 mmol/mol (6.0 to 6.4%) is often described as prediabetes or non-diabetic hyperglycaemia, though definitions vary slightly between countries.,HbA1c can be unreliable in some situations, such as pregnancy, some types of anaemia, sickle cell trait and other haemoglobin variants, and recent blood loss or transfusion. In these cases, glucose tests may be used instead.

What your numbers mean

• HbA1c: many people aim for around 48 to 53 mmol/mol (6.5 to 7.0%), but targets are individual; older or frail people may have higher targets to avoid low blood sugar
• Blood pressure: often below about 140/90 mmHg, or lower for some people with kidney disease
• Cholesterol: many people with type 2 diabetes are offered a statin to reduce heart risk
• Kidney tests: eGFR and urine ACR checked at least yearly
• Weight and waist: even modest weight loss improves glucose control

The first weeks after diagnosis

Being told you have diabetes can bring shock, guilt, fear or even relief at finally having an explanation. All of these reactions are normal. It is not your fault, and it is not a life sentence of illness. Many people find that diagnosis becomes the push they needed to make changes that leave them feeling better than before.,In the first few weeks, aim to understand the basics rather than change everything at once. Ask for your results and targets in writing, find out whether a structured education course is available near you, and book any checks you are offered. Structured education programmes, available in many countries, are one of the most useful things you can do; they teach practical skills and connect you with others in the same situation.

Food: what really matters

There is no single “diabetes diet”. The best eating pattern is one you can sustain, that helps you reach a healthy weight and keeps your glucose, blood pressure and cholesterol in range. Mediterranean-style eating, lower-carbohydrate approaches, and plant-based diets have all been shown to help when they suit the individual.,Carbohydrates have the biggest effect on blood glucose. You do not have to cut them out, but paying attention to the type and amount helps. Choose wholegrains, beans, lentils, vegetables and fruit over white bread, white rice, sugary cereals and pastries. Watch portion sizes of starchy foods such as rice, yam, cassava, potatoes, pasta and chapati, which are often the biggest part of a meal in many cultures.,Cut down on sugary drinks, including fruit juice and sweetened tea or coffee, because they raise glucose very quickly. Choose unsaturated fats such as olive or sunflower oil, nuts and oily fish. Limit processed meat and salt, which affect heart health and blood pressure.

A simple plate method

• Fill half your plate with non-starchy vegetables or salad
• Fill a quarter with protein: fish, eggs, chicken, beans, lentils, tofu or lean meat
• Fill a quarter with starchy carbohydrate, ideally wholegrain or high in fibre
• Drink water, or unsweetened tea or coffee
• Have fruit as a snack or dessert rather than juice

Physical activity

Activity helps your muscles use glucose, improves insulin sensitivity, lowers blood pressure, supports weight loss and lifts mood. Most adults are advised to aim for at least 150 minutes of moderate activity each week, such as brisk walking, cycling, dancing or swimming, plus muscle-strengthening activities on two or more days.,If that sounds a lot, start small. A 10-minute walk after meals can noticeably lower glucose rises. Breaking up long periods of sitting, for example by standing or walking for a few minutes every half hour, also helps. If you take insulin or sulfonylureas, check with your healthcare provider about avoiding low blood sugar during exercise.

Weight loss and remission

For people with type 2 diabetes who are overweight, losing weight is one of the most powerful treatments. Even 5% of body weight improves glucose control. Research such as the DiRECT trial in the UK showed that substantial weight loss, often around 10 to 15 kg, can put type 2 diabetes into remission in many people, particularly within the first few years after diagnosis.,Remission is usually defined as an HbA1c below 48 mmol/mol (6.5%) for at least three months without diabetes medicines. It is not a cure: diabetes can return if weight is regained, so regular checks continue. Approaches include structured low-calorie diet programmes, sustained lifestyle change and, for some people, weight-loss medicines or bariatric surgery. Talk to your healthcare provider before starting a very low-calorie diet, especially if you take diabetes medicines.

Medicines for type 2 diabetes

Many people need medicines alongside lifestyle changes, and needing them is not a failure. Type 2 diabetes tends to progress over time, so treatment is often stepped up.,Metformin is usually the first medicine. It lowers glucose, does not cause weight gain and rarely causes hypoglycaemia. Stomach upset is common at first; slow-release versions and taking it with food can help.,SGLT2 inhibitors such as dapagliflozin and empagliflozin lower glucose and also protect the heart and kidneys, so they are often recommended early for people with heart disease, heart failure or kidney disease. GLP-1 receptor agonists, such as semaglutide and dulaglutide, are usually injections (one is available as a tablet) that lower glucose, reduce appetite and support weight loss, with heart benefits shown for several of them. Tirzepatide acts on two hormone pathways and causes substantial weight loss.,Other medicines include DPP-4 inhibitors (gliptins), sulfonylureas such as gliclazide, which can cause low blood sugar, and pioglitazone. Insulin is used when other medicines are not enough or in certain situations such as pregnancy or illness.

Low blood sugar (hypoglycaemia)

Hypoglycaemia, usually defined as a glucose below 4.0 mmol/L (72 mg/dL), mainly affects people taking insulin or sulfonylureas. Symptoms include shaking, sweating, hunger, a fast heartbeat, irritability, confusion and blurred vision.,Treat it straight away with 15 to 20 g of fast-acting sugar, such as a glass of non-diet soft drink, glucose tablets or jelly sweets, recheck after 15 minutes and repeat if needed. Then eat a snack or meal containing starchy carbohydrate. Always carry fast-acting sugar if you are on these medicines, and tell your healthcare provider if you have frequent lows, as your treatment may need changing.

Monitoring your glucose

Not everyone with type 2 diabetes needs to check their blood glucose at home. It is usually recommended if you take insulin or sulfonylureas, are pregnant, are adjusting treatment, or are unwell. Continuous glucose monitors (sensors) are increasingly available for people on insulin and can show how food, activity and stress affect your levels in real time. Ask what is appropriate for you and what targets to aim for.

Protecting your heart

Heart attack and stroke are the leading causes of death in people with type 2 diabetes. Protecting your heart is just as important as controlling glucose. That means not smoking, controlling blood pressure, taking a statin if recommended, staying active, eating well and keeping to a healthy weight.,Some diabetes medicines, including certain SGLT2 inhibitors and GLP-1 receptor agonists, have proven heart benefits and may be chosen specifically for that reason.

Your eyes

Diabetic retinopathy is damage to the blood vessels at the back of the eye. It usually causes no symptoms until it is advanced, but it is a leading cause of sight loss in working-age adults. Regular retinal screening, often a photograph of the back of the eye every one to two years, finds changes early when treatment can prevent sight loss. Never skip your eye screening appointment, and see a healthcare provider urgently if you notice sudden changes in vision.

Your kidneys

Diabetes is one of the most common causes of chronic kidney disease and kidney failure worldwide. Yearly blood tests (eGFR) and urine tests (ACR) can find kidney damage early. Good control of blood pressure and glucose, and medicines such as ACE inhibitors, ARBs and SGLT2 inhibitors, can slow kidney damage considerably.

Your feet

Diabetes can damage the nerves in the feet so you cannot feel injuries, and reduce blood flow so wounds heal slowly. This combination can lead to foot ulcers, infections and, in the worst cases, amputation. Many amputations are preventable.,Check your feet every day for cuts, blisters, redness, swelling or colour changes, using a mirror or asking someone to help if needed. Wear well-fitting shoes, never walk barefoot, keep skin moisturised but not between the toes, and cut nails straight across. Have your feet checked by a healthcare provider at least once a year. Seek help the same day for any new wound, redness, warmth or swelling, especially if you have reduced feeling.

Nerves, sex and other complications

• Nerve damage (neuropathy) can cause tingling, burning pain or numbness in the feet and hands
• Erectile dysfunction is common in men with diabetes and is treatable; do not be embarrassed to ask
• Vaginal dryness and thrush are more common in women
• Gum disease is more common, so regular dental checks matter
• Diabetes can affect digestion, bladder control and mood
• Depression and “diabetes distress” are common and deserve support

Being unwell: sick day rules

Illness and infection usually raise blood glucose, even if you are not eating much. If you are unwell, keep drinking fluids, keep taking your diabetes medicines unless you have been told otherwise, and check your glucose more often if you have a meter.,Some medicines, including metformin, SGLT2 inhibitors, ACE inhibitors and diuretics, may need to be paused if you are vomiting, have diarrhoea or cannot drink normally, because of the risk of dehydration, kidney injury or ketoacidosis. Ask your healthcare provider for a written sick day plan. Seek urgent help if you cannot keep fluids down, your glucose stays very high, or you develop tummy pain, fast breathing or confusion.

Diabetes, fasting and religious observance

Many people with diabetes fast for religious reasons, such as during Ramadan or Lent. Fasting can be done safely by many people with type 2 diabetes, but it needs planning, especially if you take insulin or sulfonylureas, which can cause low blood sugar. See your healthcare provider a few weeks before fasting to review your medicines and agree when to break the fast for safety.

Driving, work and travel

Most people with type 2 diabetes can drive, work and travel normally. If you take insulin or medicines that can cause hypoglycaemia, check driving rules in your country, test your glucose before driving if advised, and always carry fast-acting sugar.,When travelling, carry medicines in your hand luggage, take extra supplies, bring a letter from your healthcare provider for needles and sensors, and remember that time zones and new foods can affect your glucose.

Looking after your mental health

Living with a long-term condition can be exhausting. Many people with diabetes experience “diabetes distress”: feeling overwhelmed by the daily demands of managing it. Depression and anxiety are also more common in people with diabetes.,These feelings are real and treatable. Talk to your healthcare team, ask about support groups or psychological services, and be kind to yourself on difficult days. One high glucose reading is not a failure; it is information.

Your yearly checklist

• HbA1c, usually every 3 to 6 months until stable, then at least yearly
• Blood pressure at every review
• Cholesterol
• Kidney blood test (eGFR) and urine test (ACR)
• Foot check
• Eye screening
• Weight and waist measurement
• Medicines review
• Flu vaccine every year, and other vaccines such as pneumococcal and COVID-19 as recommended
• A conversation about emotional wellbeing

Preventing type 2 diabetes in your family

Type 2 diabetes runs in families, so your diagnosis is also a chance to protect the people you love. Encourage family members at risk to get checked, especially if they are overweight, inactive or from higher-risk ethnic groups. Healthy family meals, walking together and cutting down on sugary drinks benefit everyone, including children.

Working with your healthcare team

Diabetes care works best as a partnership. Your team may include a primary care healthcare provider, a practice or diabetes specialist nurse, a dietitian, a pharmacist, a podiatrist and an eye screening service. Each has a different role, and you are the most important member of the team, because you manage your diabetes every day.

Before each review, write down your questions, any symptoms, low or high glucose readings, and changes you have made. Ask what your results mean and agree one or two goals for the next few months. If something is not working, such as a medicine that upsets your stomach or a diet you cannot stick to, say so. There is almost always another option.

Frequently asked questions

Can type 2 diabetes be cured?

There is no cure, but it can go into remission, particularly with significant weight loss early after diagnosis.

Is eating sugar the cause of diabetes?

Not directly. Type 2 diabetes is mainly linked to excess weight, inactivity, genetics and age, though sugary drinks increase risk.

Do I have to give up rice, yam or bread?

No. Focus on portion sizes, wholegrain options and pairing them with vegetables and protein.

Will I need insulin eventually?

Some people do as diabetes progresses, but many manage for years with lifestyle and tablets. Needing insulin is not a failure.

Can I drink alcohol?

Usually in moderation, with food. Alcohol can cause low blood sugar if you take insulin or sulfonylureas.

But I feel completely fine. Do I really need to change anything?

Type 2 diabetes damages blood vessels silently for years before symptoms appear. Feeling well is exactly the right time to act, because the changes you make now protect your heart, eyes, kidneys and feet for decades.

Related: Early signs of type 2 diabetes · Metformin explained · SGLT2 inhibitors · Blood sugar levels chart

Sources: World Health Organization, International Diabetes Federation Diabetes Atlas, National Institute for Health and Care Excellence (NG28), American Diabetes Association Standards of Care, Diabetes UK, DiRECT trial (The Lancet).