Type 2 diabetes

Type 2 diabetes is a condition that makes your blood glucose (sugar) levels too high caused by insulin resistance and sometimes reduced insulin production. It’s also known as Type 2 diabetes mellitus.

By Wallace Health I Medically reviewed by Adrian Roberts.
Page last reviewed: October 2018 I Next review due: October 2023

What is type 2 diabetes

In type 2 diabetes, your body becomes resistant to insulin, and sometimes your pancreas can't produce enough of it. Symptoms take weeks or months to develop as your body can still make insulin, unlike in type 1 diabetes.

Insulin is a hormone created in your pancreas that regulates glucose levels by allowing it to be absorbed into your body's cells for use or storage. Glucose (a type of sugar) gives you energy and helps your body function normally. When it can’t be absorbed by your body's cells, it builds up in your bloodstream, which can be very dangerous.

This can cause symptoms such as excessive thirst, needing to urinate frequently and tiredness. Untreated type 2 diabetes also increases your risk of serious long-term damage to your eyes, feet, heart, kidneys and nerves. 

It can affect your everyday life and is a condition you will need to manage for the rest of your life — dietary changes, medication and regular check-ups are often needed. Type 2 diabetes is linked to: 

  • Being overweight 
  • Having a family history of type 2 diabetes
  • Having an inactive lifestyle

The first treatment recommended for type 2 diabetes is usually changing your diet, more physical activity and weight control.

Diabetes affects around four million people in the UK. Around nine in 10 people who have diabetes have type 2. 

Type 2 diabetes was formerly called non-insulin-dependent diabetes or maturity-onset diabetes. It usually develops in people aged over 40 but can develop at any age, including in children. More and more people are being diagnosed in the UK as it is more common if you are overweight or obese

Type 2 diabetes can also run in families. It is around five times more common in people of South Asian, African or Afro-Caribbean descent and in this group, often develops before age 40. 

Around 750,000 people in the UK are estimated to have type 2 diabetes but have not yet been diagnosed.

How to tell if you have type 2 diabetes

You can have type 2 diabetes but not realise it as it doesn’t always make you feel unwell. Also, as symptoms develop gradually, you may get used to them and therefore not notice that you are ill. Some people may not have any obvious symptoms as their blood glucose levels are not too high but they are still at risk of complications and need treatment. 

Signs of diabetes include feeling very tired, especially after eating a meal and feeling extremely thirsty. You might also need to urinate more than usual, especially at night. 

Extreme thirst and frequent urination occur because when you have high blood sugar levels, the excess sugar leaks into your urine, which draws out extra water with it through your kidneys.

Other type 2 diabetes symptoms include:

Your vision may also be blurry and cuts or wounds may take longer to heal.

Talk to your doctor if you’re concerned about symptoms

You can book an appointment with a Spire private GP today.

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Diagnosis and tests for type 2 diabetes

As people often do not realise they are ill with type 2 diabetes, it is often diagnosed after having blood or urine tests for another health problem. If you have symptoms, see your GP as soon as possible. They will talk to you about your symptoms and carry out tests to check your glucose levels. 

Although a simple dipstick test to detect sugar levels in a sample of your urine can suggest diabetes, a blood test is needed to confirm the diagnosis. High blood sugar levels will confirm that you have diabetes. You may need to have more than one blood sample taken for your blood tests. These tests may include:

  • Fasting blood sugar test — after you’ve gone without food overnight
  • Glycated haemoglobin (HbA1c) test to check average blood sugar levels over the past few months — a result of 48mmol/mol (6.5%) or above means you have diabetes
  • Oral glucose tolerance test — after you’ve gone without food overnight and then have a sugary drink so your glucose levels can be tested
  • Random blood sugar test to check your glucose levels

If the tests show you have diabetes, your GP may carry out more tests to identify whether you have Type 1 or Type 2 diabetes. After your diagnosis, they will explain what diabetes is and how high blood glucose levels will affect your health. They will also discuss treatment, which may include:

  • Changes to your diet and exercise levels
  • Changes to your lifestyle eg reducing alcohol and quitting smoking
  • Whether you need diabetes medication

It can feel overwhelming when you receive your diagnosis and you may not be able to take in all the information your GP gives you. Take some time after your appointment to talk to your friends and family about what you've been told and make a list of questions you have. You can then arrange another appointment with your GP to ask these questions.

What usually happens after diagnosis

Usually, your GP will prescribe medication to treat your diabetes. It can take some time to adjust to the medication and your GP may need to prescribe different doses to find the right one. 

You will most likely need to attend regular check-ups for type 2 diabetes, become more active and change your diet. You will also need to pay attention to signs of other health problems so you can avoid them developing into serious conditions.

Ask your GP about where you can access free education courses on type 2 diabetes. 

Causes of type 2 diabetes

The primary causes of type 2 diabetes are not exercising enough and being overweight or obese. If you are overweight or obese, where in your body your excess weight is stored is important. Carrying extra weight around your tummy (central obesity) may be caused by excess sugar being pushed into fat cells in your tummy area over the years. If you’re a man, your risk of diabetes is, therefore, higher if your waist measures more than 94cm. If you’re a woman, your risk is higher if your waist measures more than 80cm. 

You’re also more likely to get type 2 diabetes if you:

  • Are aged over 40 or are South Asian, African or Afro-Caribbean and aged over 25
  • Have a family history of it ie a close family member (parent, sibling or child) has type 2 diabetes
  • Have another medical condition such as polycystic ovary syndrome or metabolic syndrome
  • Have pre-diabetes — when your blood glucose levels are high but not high enough to be diagnosed with diabetes; this is called impaired glucose tolerance and puts you at high risk of developing diabetes
  • Take certain medications eg statins

You are also at higher risk if you had pre-diabetes or diabetes when you were pregnant (gestational diabetes).

Common treatments for type 2 diabetes

You may be able to manage your diabetes symptoms by reducing your weight and having a healthy diet. Increasing the amount of exercise you do can also help. Your GP may prescribe tablets or insulin to control your blood glucose levels.

Most people need medication to control their type 2 diabetes. Medication will help maintain your blood glucose levels as close to normal as possible to prevent complications from your diabetes. You may need to take medication for the rest of your life. 

As diabetes usually worsens over time, your medication may need to be changed to something stronger or your dose may need to be increased. 

You may need to try several different medications, as prescribed by your GP, before you find one that is right for you. In most cases, a drug called metformin is prescribed first. You may end up needing to take several medications. Insulin is not usually prescribed in the early stages of type 2 diabetes and is usually only given when other medications have stopped working. 

If you are prescribed insulin, your GP or nurse will show you how to inject yourself or use an insulin pump. If you need to lose a lot of weight, your GP may refer to you a weight management service or consider whether obesity surgery, such as a gastric bypass or gastric sleeve, might help.

Side effects of diabetes medications and insulin

You may not have any side effects from your medication. However, if you do, speak to your GP or nurse — do not stop taking your medication without first getting medical advice.

Side effects include:

  • Bloating and diarrhoea
  • Feeling nauseous
  • Swelling caused by fluid build-up under your skin — this can occur in one or more parts of your body 
  • Weight loss or weight gain

Whether you take medication or insulin, it is important to be aware of the side effect hypoglycaemia, commonly referred to as 'having a hypo'. This occurs when your blood glucose level drops too low, usually under 4mmol/L. Some medications eg metformin tablets do not cause hypoglycaemia.

You may develop hypoglycaemia if you: 

  • Delay or miss a meal or snack
  • Take part in unexpected exercise or physical activity 
  • Take too much diabetes medication

If you do not take any medication or insulin and manage your diabetes through your diet alone, you can't develop hypoglycaemia.

Free prescriptions

If you have been diagnosed with diabetes, you're entitled to free prescriptions for your diabetes medication or insulin. You will need to apply for an exemption certificate by completing a PF57 form provided by your GP surgery. It will take about a week to receive your certificate in the post and it will be valid for five years. 

To claim your free prescriptions, take your certificate to your pharmacy with your prescriptions. 

If you need to fill a prescription before you have a certificate, keep the receipts from paying for your prescriptions so you can claim the money back — you can send these receipts along with your completed PF57 form.

Going on holiday

If you're going on holiday, make sure you: 

  • Pack extra medicine — check with  your GP or nurse about how much to take
  • Pack your medicine in your hand luggage in case the bags you check in are damaged or lost

If you're flying and need to take insulin injections with you, get a letter from your GP stating that you need the injections to treat your diabetes.

Food and keeping active

Eating healthily and staying active will help you control your blood glucose levels and your weight, and protect you against other health conditions, such as heart attacks and stroke. Even if you take medication for your diabetes, lifestyle changes are essential to successfully manage your condition.  

Changing your diet, controlling your weight and regular exercise are often enough to help people with type 2 diabetes reduce their blood glucose levels. However, if your blood sugar levels are still high after trying these measures for several months, your GP will recommend medication in addition to your lifestyle changes.

A diabetic diet

If you have diabetes, you can eat all types of food but there are some you should limit, including high-fat, high-sugar and high-salt foods. Changing your diet all at once can be difficult. You can try making small changes every week and getting advice from a dietitian. It is important to eat a variety of foods, including fruits and vegetables and some starchy foods, such as pasta and rice. Make sure you do not skip meals; eat breakfast, lunch and dinner every day.

For some people, there is evidence that following a low-calorie diet (800–1,200 calories) for around 12 weeks can reduce symptoms of diabetes.  However, low-calorie diets are not safe for everyone eg if you take insulin for your diabetes. Talk to your GP before you try a low-calorie diet. 

Physical exercise

Aim for two and a half hours of physical activity each week. Whichever activity you choose, make sure it is vigorous enough to make you mildly out of breath and mildly sweaty eg climbing stairs, brisk walking, strenuous gardening or housework. 

If you are able, try to exercise more frequently and vigorously eg try cycling, dancing, jogging or swimming. You don't need to complete your daily exercise in one go, you can do short bursts of activity throughout the day eg two 15-minute brisk walks. 

Losing weight

If you are overweight or obese, losing weight will help reduce your blood glucose levels and improve your blood pressure and cholesterol. To find out if you are overweight, you can calculate your body mass index (BMI) — a BMI of 25 or more is considered overweight. If you need to lose weight, do so gradually — aim to lose half to one kilogram each week. It may not be realistic to achieve your ideal weight but any amount of excess weight you lose will help control your diabetes. 

Reducing other risk factors

To avoid developing complications from your diabetes, there are several other risk factors you can address. This includes: 

  • Getting an annual flu vaccination and a one-off pneumococcal vaccination — these infections can be more severe if you have diabetes
  • Maintaining a healthy blood pressure — get your blood pressure checked regularly as even slightly raised blood pressure combined with your diabetes puts you at greater risk of other health complications; weight loss and exercise will help keep your blood pressure down but you may also need to take two or three medications 
  • Quitting smoking — smoking is a major risk factor for several health complications; ask your GP or nurse for support to quit, such as attending a smoking cessation clinic, taking medication or having nicotine replacement therapy

Going for regular check-ups

Once you are diagnosed with diabetes, you will need to attend special diabetes clinics — most GP surgeries and hospitals have these. A multidisciplinary team of healthcare workers will provide advice and check on your progress. This may include: 

  • Dieticians
  • Doctors and nurses who every year will check your blood pressure, cholesterol and kidney function — this is to detect high blood pressure, and heart and kidney disease
  • Specialists in eye health (optometrists) who every year will check for damage to blood vessels in your eyes and your retina by taking photos of the back of your eye — diabetic retinopathy is caused by diabetes and its progression can be stopped; glaucoma is more common in diabetics and can be controlled with treatment; if you have blurred vision, see your GP immediately 
  • Specialists in foot care (podiatrists) to check for any numbness, infections and ulcers every year — this can also be done by your GP or diabetic nurse; if you have bruises, cuts or numbness in your feet, see your GP immediately 

A doctor or nurse will also need to perform a glycated haemoglobin (HbA1c) test on you every three months after you've first been diagnosed. This will check your average blood sugar levels over the last few months by measuring a part of your red blood cells to which glucose attaches. Once your blood sugar levels are stable, you will have this test every six months. 

Effective treatment should lower your HbA1c levels to below a target level, ideally less than 48mmol/mol (6.5%). It may not be possible to reach levels as low as this — your doctor will agree on a realistic target with you. If you can’t reach your target, your doctor may recommend adjusting your treatment eg increasing the dose of medication you take.

In some cases, your doctor may recommend regularly checking your blood glucose levels yourself at home — they will provide instructions on how to do this. 

Health problems

Type 2 diabetes can cause other health complications. It is therefore important to: 

  • Be aware of signs of other health conditions and report these to your GP or nurse
  • Control your blood sugar levels
  • Have regular check-ups at your diabetes clinic

Type 2 diabetes can cause: 

  • Foot problems eg sores and infections
  • Heart disease and stroke
  • Kidney problems 
  • Loss of vision and blindness
  • Nerve damage — this causes loss of feeling and/or pain
  • Sexual problems eg difficulty getting or keeping an erection

If you are pregnant, diabetes may increase your risk of miscarriage and stillbirth, depending on how well-controlled your blood glucose levels are.

Heart problems

Your cholesterol and blood pressure should be checked at least once a year. This is because diabetes increases your risk of heart disease and stroke — high blood pressure and cholesterol contribute to these conditions and should be caught early and treated. If you are already taking medication for high blood pressure and high cholesterol, you should continue taking them. 

Diabetes also worsens the effect smoking has on your heart and increases the risk of your arteries hardening (atheroma), which can cause angina, heart attacks, poor circulation and stroke.

Loss of feeling

If you notice any numbness in any part of your body, tell your GP or nurse. Diabetes can cause nerve damage (neuropathy), which can affect any part of your body, particularly your feet. Neuropathy causes: 

  • Constipation or diarrhoea
  • Numbness
  • Pain or tingling
  • Sexual problems

Getting treatment early can stop nerve damage worsening. 

Foot problems

Check your feet every day for bruises, cuts, infections and ulcers. Diabetes can reduce the blood supply to your feet, which causes numbness. You may therefore not notice if your foot is injured or sore, which can cause infections and ulcers to develop. To help keep your feet in good condition, make sure you: 

  • Avoid walking barefoot outside to avoid scrapes and cuts to your feet
  • Keep your feet clean and dry — this will reduce your risk of infection
  • Wear well-fitting shoes

See your GP or nurse if you notice changes in your feet, including:

  • Blisters, cracks or cuts
  • Pain or tingling
  • Numb toes and feet

Your feet should also be checked every year by your GP, nurse or podiatrist. Any sores or infections that aren't treated early can cause gangrene, which will usually need amputation — diabetes is responsible for around 175 amputations every week in England.

Eye problems

Your eyes should be checked every year for damaged blood vessels. Damaged blood vessels can cause diabetic retinopathy — an eye disease that can cause vision loss and blindness. Regular eye checks with your optometrist can detect damaged blood vessels before the damage affects your vision. Early treatment can therefore prevent vision problems. See your GP immediately if you notice:

  • Blurred vision, particularly at night
  • Floaters — small shapes, often described as cobwebs, strings or specks, which appear in your vision
  • Sensitivity to light


If you are planning on getting pregnant, speak to your GP or diabetic healthcare team. Having type 2 diabetes doesn't mean you can't have a safe pregnancy and birth but you will need additional check-ups during your pregnancy.

You may not develop any complications — your risk of complications is lower the closer your blood glucose levels are to normal and if you have taken steps to reduce other risk factors, such as high blood pressure. If you do develop complications, the type and severity will depend on your particular circumstances.

Finding help and support for type 2 diabetes

Free education courses are available where you can learn more about type 2 diabetes and how to manage it. Your GP can refer you onto a course or you can call your GP surgery to get a referral letter. 

There are also local support groups organised by Diabetes UK where you can learn tips and techniques on coping with diabetes on a daily basis, such as changing your diet, exercising and managing emotional problems such as depression. You will have the chance to talk to others in a similar position as you and share information on how you each deal with diabetes. 

Reputable online forums, blogs and apps can be a good source of support and advice too, such as: 

  • Diabetes.co.uk forum — offers discussions on living with and managing diabetes
  • Diabetes Chat — scheduled chats with healthcare professionals and chatrooms to connect with others who have diabetes
  • Diabetes UK blogs — blogs on a range of topics including diabetes and work, eye health and food
  • NHS Apps Library — a catalogue of apps including ones to help manage your diabetes and connect with lifestyle coaches

Telling the DVLA

If you take insulin for your type 2 diabetes, you need to tell the DVLA. This is because taking insulin puts you at risk of developing hypoglycaemia, which affects your ability to drive. If you don't tell the DVLA, you can be fined.

Telling others 

Although it can be difficult to tell people you have diabetes, it can be helpful to tell certain individuals, such as: 

  • Your colleagues or employer in case of an emergency
  • Your family — they can provide support; if you live with your family, they can help you with making the necessary dietary changes
  • Your partner — getting a diagnosis of diabetes can affect your mood and it can be helpful to share how you feel with your partner

Carry a medical ID

In case of emergency, you may want to wear a special wristband or carry a card in your wallet stating that you have diabetes. If you are not conscious, it can help others to know you have diabetes as it may affect any treatment you receive.

Type 2 diabetes and coronavirus

Having type 1 or type 2 diabetes does not increase your risk of catching coronavirus. Most people who get coronavirus will have mild symptoms and will not need to go to hospital. 

However, if you have diabetes, your risk of developing severe illness with coronavirus is higher — the effects will vary from person to person. In children, the risk of serious illness remains low. 

Illness can make it hard to control your blood glucose levels. To fight the illness, your body releases stores of glucose in your cells into your bloodstream — this is done to give you energy. However, diabetes means you can't make enough or any insulin so your blood sugar levels rise. While you are fighting an illness, it, therefore, is harder to manage your diabetes, which puts you at greater risk of having major blood glucose highs and lows — this can lead to serious conditions, including diabetic ketoacidosis (DKA) and hyperosmolar hyperglycaemic state (HHS). 

Some people will develop serious illness from coronavirus with the risk of dying. There are factors that put you at greater risk of serious illness with coronavirus, including: 

  • Being of African, Afro-Caribbean, Asian or minority ethnic descent
  • Being older
  • Having a BMI over 30
  • Having a history of high glycated haemoglobin (HbA1c)
  • Having heart failure or kidney disease

Some risk factors can't be changed but others can be reduced. 

If you get coronavirus, it is important to follow your sick day rules to control your blood glucose levels as much as possible. This will give you the best chance of staying strong enough to fight off the virus. 

Frequently asked questions

What does diabetes type 2 mean?

Type 2 diabetes means your body has become resistant to insulin. This means although you can still make insulin, your body doesn’t respond to it. Insulin helps glucose (sugar) in your blood move into your cells for use or storage. In type 2 diabetes, levels of glucose in your blood are high, which can damage your tissues.

How do you get type 2 diabetes?

The biggest risk factors for developing type 2 diabetes are being overweight, having a family history of diabetes and having an inactive lifestyle.

Can you get rid of type 2 diabetes?

Type 2 diabetes is a lifelong condition. However, you can reduce and control your blood glucose (sugar) levels through eating a healthy diet, controlling your weight, exercising regularly and if needed, taking medication. If your diabetes is well-controlled, you can live a full life.

Which is worse type 1 or 2 diabetes?

In many cases, type 2 diabetes is milder than type 1 diabetes. However, it can still cause serious health complications, especially if it is not well-controlled.

How long can you live with type 2 diabetes?

Type 2 diabetes may reduce your life expectancy by up to 10 years. However, this means you can still expect to live into old age.

What is the leading cause of type 2 diabetes?

There are two main causes of type 2 diabetes — your family history of the condition ie having a parent, sibling or child with type 2 diabetes, and your lifestyle ie being overweight and physically inactive.

How can I lower my sugar level quickly?

It is dangerous to take extra medication to lower your sugar levels quickly as this may cause hypoglycaemia, where your blood sugar levels drop too low. However, you can lower your sugar levels in the long-term by eating a healthy diet, controlling your weight and exercising regularly.

What foods can reverse diabetes?

There aren’t any foods that can reverse diabetes but changing your diet can help you better manage your condition. This includes avoiding high-fat, high-sugar and high-salt foods, as well as eating a variety of food types including fruits, starchy foods (eg pasta, rice) and vegetables. Also, make sure you don’t skip meals.

Is type 2 diabetes serious?

Yes, type 2 diabetes is a serious condition. If left untreated, it can damage tissues throughout your body, including your eyes, heart, kidneys and nerves. This can cause serious health conditions, such as heart disease, kidney disease, neuropathy and vision loss.

Can you get diabetes from eating too much sugar?

No, eating too much sugar does not directly cause diabetes. However, it can cause weight gain and being overweight or obese is a major risk factor for diabetes.

What does a diabetic attack feel like?

A diabetic attack can happen when your blood glucose levels become too high (hyperglycaemia) or too low (hypoglycaemia).

If you have hyperglycaemia, you may feel confused, dizzy, hungry, irritable or anxious, nauseous and/or tired. You may also get the chills and/or be sweaty, feel faint and have headaches.

If you have hypoglycaemia, you may feel thirsty and tired and have headaches. You may also need to urinate more often and have blurry vision.

How do you know if it's type 1 or 2 diabetes?

Type 1 diabetes is usually diagnosed before age 40 and often in childhood, while type 2 diabetes is often, but not always, diagnosed after age 40 — it is increasingly diagnosed in children due to more children being overweight. It is hard to tell which type of diabetes you have based on your symptoms alone. In most cases, your GP will refer you for a series of blood tests to determine which type you have.

Can type 2 diabetes make you lose weight?

Yes, uncontrolled type 2 diabetes can cause weight loss.