Type 2 diabetes

Expert reviewer, Dr Jonathan Katz, Consultant Endocrinologist
Next review due June 2021

Type 2 diabetes is a condition in which your body can’t control the amount of glucose (sugar) in your blood. Your body doesn’t respond to insulin properly, and you may not produce enough. This causes your blood glucose level to become too high.

About type 2 diabetes

Insulin is a hormone (a chemical made by your body) that controls the amount of glucose in your blood. It helps glucose move from your blood into your body tissues – like your muscle cells – when you need a quick form of energy. If your body is not responding to insulin properly, your blood glucose level can become too high. If you have type 2 diabetes, your body stops reacting to insulin properly, and you may not produce enough.

There are two main types of diabetes: type 1 and type 2. Type 2 diabetes is the most common. About 3.5 million people in the UK are diagnosed with diabetes, and of these, more than nine out of 10 have type 2 diabetes.

Type 2 diabetes is more common among older people, but you can develop it at any age. It’s becoming more common in young adults and children, and is usually linked to being overweight and not very active.

Symptoms of type 2 diabetes

If you have type 2 diabetes, you may not have any obvious symptoms. Your diabetes may only be discovered during a routine medical check-up with your GP.

If you do have symptoms of type 2 diabetes, you may:

  • go to the toilet (to wee) more often than usual
  • feel constantly thirsty
  • have changes in your weight for no obvious reason
  • feel extremely tired
  • have blurred vision
  • regularly get genito-urinary infections, such as thrush, or urinary tract infections, such as cystitis

If you have any of these symptoms, see your GP.

Diagnosis of type 2 diabetes

Your GP will ask about your symptoms and examine you. They may ask you to have a blood test to check the level of glucose in it in the following tests.

  • Glycosylated haemoglobin (HbA1C) test. Your HbA1C level is a measure of how much glucose has been taken up by your red blood cells. It can show if you’ve had high blood glucose levels over a long period of time.
  • A random glucose test. This involves taking a sample of your blood to test how much glucose it contains. If you have a level of glucose in your blood that's more than 11mmol/L, you're likely to have diabetes.
  • A fasting blood glucose test. You can’t eat anything for at least eight hours before you have this test. If you have a level of 7mmol/L or more in your blood in this test, you may have diabetes.

If your blood test results suggest that you have type 2 diabetes, your GP may advise you to have the tests again to confirm your diagnosis.

If you're diagnosed with type 2 diabetes, you may be referred to a specialist diabetes clinic. The doctors and nurses there will give you advice and support so you can manage your diabetes at home. You’ll have a check-up every year to see how you’re getting on.

Treatment of type 2 diabetes

Treatment for type 2 diabetes aims to control your blood glucose level. This may be with changes to your lifestyle and if necessary, medicines.

As soon as you’re diagnosed with type 2 diabetes, your GP may refer you to a group education programme. One example of these is a DESMOND (Diabetes Education for Self-Management for Ongoing and Newly Diagnosed) programme. Both you and your family can attend to learn about diabetes and how to manage your care.


You can help to control your blood glucose level by making some changes to your diet and trying to be more physically active.


Your doctor may recommend you try medicines if lifestyle changes alone don’t keep your blood glucose level under control. There are different types of diabetes medicines available.

Your doctor will usually begin by offering you a medicine called metformin. Metformin works by reducing the amount of glucose that’s released from your liver into your blood. It also improves the way your muscles use glucose.

If metformin doesn’t help you manage your blood glucose level, or you get bad side-effects, your doctor can prescribe other medicines instead. Sometimes, you’ll need to take more than one of these medicines at a time. These include the following.

  • A sulfonylurea medicine, such as gliclazide, glipizide and glimepiride. These help your pancreas to produce more insulin.
  • DPP-4 (dipeptidyl peptidase) inhibitors, such as sitagliptin, saxagliptin or linagliptin. These help your body to produce insulin when it’s needed.
  • Pioglitazone. This helps to improve how your body responds to insulin.
  • Sodium-glucose co-transporter 2 (SGLT-2) inhibitors including dapagliflozin, empagliflozin and canagliflozin. These tablets can lower your blood glucose.
  • Glucagon-like peptide 1 (GLP-1) agonists, such as exenatide or liraglutide. You have these as an injection and they work by helping your body to make more insulin. They can also help you lose weight.

For more information about medicines for type 2 diabetes, speak to your doctor or diabetes specialist nurse.

Insulin injections

Your doctor may suggest you have insulin injections if lifestyle changes and medicines can’t keep your blood glucose level under control.

You’ll usually need to inject yourself with insulin – sometimes several times a day – using either a small needle or a pen-type syringe with replaceable cartridges. You can be prescribed several different types of insulin. Some work more quickly than others and they act for different lengths of time. Your doctor or nurse will advise you which type is best for you.

You usually inject insulin into your upper arm, thighs, buttocks or tummy (abdomen) before you have meals. It’s best to change the exact spot that you use within the injection site each time. This is because insulin can cause fat to grow more quickly around the injection site, causing soft lumps to build up under your skin. Insulin can have a number of other side-effects. If you take too much insulin, for example, you can develop hypoglycaemia – a ‘hypo’, which means low blood glucose. See Complications of type 2 diabetes below for more information about this.

If you have insulin injections, your doctor or nurse will suggest that you monitor your blood glucose level with a glucose meter at home. This involves taking a pinprick of blood from your finger and putting a drop on a testing strip. You might find it helps to wash and dry your hands in warm water beforehand so your blood flows more freely. You place the testing strip into the glucose meter, which reads it and shows you the result automatically. Your GP or diabetes specialist nurse will talk you through how to do this, and tell you how often you need to check your glucose level. Monitoring your blood glucose level will help you understand how to adjust your insulin dose according to how much carbohydrate you eat.

Your 'normal' blood glucose range will be specific to you, but a general guide for adults is:

  • when you wake up and before you have breakfast: 5 to 7mmol/litre
  • before you have meals at other times of the day: 4 to 7mmol/litre

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Causes of type 2 diabetes

Your risk of developing type 2 diabetes can be increased by several things. These include:

  • being overweight or obese
  • having a close family member with the condition
  • if your family is originally African–Caribbean or South-Asian
  • being over 40 – your risk increases with age
  • having high blood pressure or too many fats in your blood
  • if you’re blood tends to clot more than usual
  • not exercising regularly
  • smoking
  • if you’re a woman, having polycystic ovary syndrome
  • for women, having previously developed diabetes during pregnancy (gestational diabetes)

If you regularly eat a poor diet, it may also increase your risk of developing type 2 diabetes. This might be a diet that doesn’t contain much fibre, for example. A high glycaemic index (GI) diet may also make you put on weight, which in turn, increases your risk of type 2 diabetes. You can learn more about GI foods in our infographic below.

Complications of type 2 diabetes

If you don’t have good control of your blood glucose level, it may become too high, which is called hyperglycaemia. Mild hyperglycaemia doesn’t usually cause any symptoms. But if it gets worse, you may find that you’re thirstier than usual. You may go to the toilet more often (to wee) and feel tired as your blood glucose level continues to rise.

Over time, if your blood glucose isn’t controlled properly and stays too high, it can lead to a number of problems. These include:

  • kidney failure
  • nerve damage, which can cause tingling or burning sensations, or cause numbness and make you lose your sense of touch or temperature altogether
  • damage to your vision, which could even make you blind
  • heart disease
  • stroke
  • peripheral arterial disease
  • foot ulcers – which can eventually lead to foot or lower leg amputation
  • persistent or regular infections, such as skin, or urine infections
  • dementia

Very rarely, your blood glucose can rise to a dangerously high level. This can lead to a condition called hyperosmolar hyperglycaemic state. If this happens, you may become very dehydrated and lose consciousness. Although the risk of this condition is low, it’s a medical emergency and you’ll need to be treated in hospital.


Hypoglycaemia is a possible complication of treatment for diabetes. Your blood glucose level can become too low if you don't eat enough carbohydrate while taking insulin, or medicines called sulfonylureas. This is called hypoglycaemia, or a ‘hypo’. You’re also more likely to develop hypoglycaemia if you miss a meal or are taking other medicines such as beta-blockers, drink too much alcohol or do more physical activity than usual.

Most people get warning signs before hypoglycaemia. You might:

  • feel hungry
  • sweat a lot
  • feel your heart pounding
  • feel anxious or irritable
  • get tingling lips
  • feel tired, or confused
  • have blurred vision

If you develop hypoglycaemia, take glucose tablets or gels, or drink a glass of milk or juice straightaway. After 10 to 15 minutes, test your blood glucose level to see if it's returning to normal. If it hasn’t, have something more to drink or take more glucose tablets and re-test your blood glucose levels after another 15 minutes. Once your blood glucose levels start to get back to normal, eat something that contains longer-lasting carbohydrates such as a sandwich, or some biscuits. Or if you’re about to have your next meal, have some extra potatoes or pasta with it.

If your blood glucose level doesn’t return to normal and you still have symptoms of hypoglycaemia, call for emergency help immediately.

If you don't take steps to deal with hypoglycaemia, it can eventually cause you to have a fit and you’ll lose consciousness. If it’s very severe, hypoglycaemia can be fatal, so it’s essential that you can recognise the signs and know how to treat them. Your healthcare team may give you a prepared injection of a medicine called glucagon to take if you have a hypo and lose consciousness. They’ll show a family member or friend how to use it.

It’s a good idea to wear a medical emergency identification bracelet or similar, so that people know you have diabetes.

If you’re having hypos quite a lot, your doctor or specialist diabetes nurse may recommend you get some extra help. They may refer you to a Blood Glucose Awareness Training (BGAT) programme.

Living with type 2 diabetes

It’s important to try to follow as healthy a lifestyle as you can if you have diabetes. This may help to control your glucose level, and reduce your risk of developing complications.

  • Eat a healthy, balanced diet and take regular exercise, as recommended by your doctor or diabetes specialist nurse.
  • If you drink alcohol, stick within recommended, sensible limits. And make sure you don’t drink on an empty stomach.
  • If you smoke, try to stop. Smoking is unhealthy for everyone, but it's especially bad if you have diabetes. Diabetes increases your risk of developing circulatory problems, heart disease and stroke. Your risk of these conditions is even higher if you smoke and have diabetes too.
  • Aim to maintain a healthy weight.

You’ll be offered a check-up at least every six months to make sure that your blood glucose level is under control. Your doctor will suggest you have regular blood tests for glycosylated haemoglobin (HbA1C). HbA1C is a measure of how much glucose has been taken up by your red blood cells. It shows how high your blood glucose level has been, or how well you’ve been controlling it over the previous two to three months.

It’s important to have regular eye examinations, dental check-ups, foot checks, cholesterol tests and blood pressure checks. This will help to diagnose any complications early on so that they can be treated. It’s also a good idea to have an annual flu vaccination and a pneumococcal vaccination if you have diabetes.

Being diagnosed with a long-term medical condition, such as diabetes, can be difficult to come to terms with. It’s important to discuss your feelings with your specialist diabetes nurse or GP as they can talk through any concerns you have. It may also help to talk to other people with diabetes to get tips and advice on how they manage their condition. Support groups like Diabetes UK (see Other helpful websites below for contact details) are a good start website to find and can put you in touch with a local group.

Glycaemic index

You can help to control your blood glucose level by making some changes to your diet. Aim to eat more high-fibre, low-glycaemic index sources of carbohydrate and low-fat dairy products and oily fish. And eat less foods that contain saturated and trans fatty acids. An explanation of the glycaemic index and examples of low GI foods is given below.

Click to open a PDF version of Bupa's Glycaemic index (0.6MB)


Frequently asked questions

  • You don’t need to let the Driver and Vehicle Licensing Agency (DVLA) know you have type 2 diabetes if you manage it with lifestyle changes and you don’t take any medicines. If you do take medicines and your diabetes is under control, you should be able to drive a car or motorbike as normal.

    You need to contact the DVLA if you take any medicines to treat type 2 diabetes that put you at risk of having a hypo (hypoglycaemia). You also need to let them know if you have any complications, such as eye problems or nerve damage to your legs or feet, or you lose awareness of a hypo. The DVLA may contact your doctor for more information.

    You must make sure that you can safely control a car at all times. To reduce your risk of having a hypo while driving, here are some tips.

    • Check your blood glucose before you start driving, even if it’s a short one.
    • Don’t drive for more than two hours without checking your blood glucose level again.
    • Keep some kind of fast-acting carbohydrate, such as sweets and a sugary drink, in your car.

    If you start to feel you’re having a hypo while you're driving:

    • pull over and stop somewhere safe
    • take glucose tablets or some other form of fast-acting carbohydrate immediately
    • don't start driving again until 45 minutes after your blood glucose level is back to normal

    The rules are stricter to drive a heavy goods vehicle or passenger vehicle (such as a minibus) – contact the DVLA for more information.

  • Your aim is to keep as healthy as possible by maintaining a healthy weight, keeping active, following a healthy diet and not smoking. You have a large part to play in the control of your condition, so it's important that you understand and follow your treatment plan.

    It's important to keep your blood glucose level, blood pressure reading and cholesterol (lipid) level as near to normal as possible. This will make you less likely to develop short- or long-term health problems associated with diabetes. Having high blood pressure or high blood cholesterol can increase your risk of developing heart problems or having a stroke.

    Here’s a brief guide of what you should be aiming for.

    • Blood glucose level before meals of five to seven mmol/litre. Your GP will advise you on whether or not you can monitor your blood glucose level yourself at home.
    • Blood pressure of 140/80mmHg or below. You should be able to keep your blood pressure well controlled with lifestyle changes and medicines.
    • A stable HbA1c level of around 48mmol/mol. But check with your doctor as this can depend on your individual circumstances, and how you manage your diabetes. You’ll be offered an HbA1c blood test at least every six months. This measures how well you’ve been controlling your blood glucose level over the last two to three months.
    • Total blood cholesterol level of less than 4mmol/litre. Your doctor will suggest ways to keep your cholesterol level under control. You may be prescribed medicines to lower your cholesterol level.

    Type 2 diabetes can gradually get worse as time goes on. This means that in future you may need to increase the amount of medicines you take. Your doctor may also suggest that you move on to insulin, to keep your condition well controlled.

  • Yes it can, if you don’t control your blood glucose level.

    If your diabetes isn’t managed properly, you’re likely to have higher than normal blood glucose levels. Over time, the high blood glucose levels damage your nerves, blood vessels and tissues, which is called neuropathy. Neuropathy is a common complication of diabetes.

    Early signs of diabetic neuropathy include tingling, pain, numbness or weakness in your toes and fingers. As the nerve damage progresses, it can cause erectile dysfunction in men. In women, the nerve damage can cause loss of sensation and affect sexual arousal, and may make sex painful.

    You’re more likely to have sexual problems if you’re overweight or have high blood pressure or high cholesterol. Psychological problems such as feeling anxious or stressed can also influence your sex drive and ability to get and keep erections.

    If you’re having sexual problems, go and see your GP to get some help and advice.

  • There’s no reason why you can’t travel if you have type 2 diabetes. You just need to take some steps to stay safe.

    You’ll need to let your travel insurance company know that you have diabetes so you get appropriate cover. If you’re heading to a country within the European Union, you can apply for a European Health Insurance Card (EHIC) to get free or reduced-cost emergency treatment. But you’ll still need travel insurance in addition to this.

    Here are some tips for when you’re on the go that might be useful to you (depending on your individual circumstances).

    • Always carry some identification that states you have diabetes. You could wear a medical emergency identification bracelet or similar, so that people know you have diabetes.
    • Keep some form of fast-acting carbohydrate in your hand luggage in case you have a hypo. If you take insulin to treat your diabetes, carry this in your hand luggage too – and a spare set on you.
    • It’s best to stick to sensible limits when it comes to alcohol.
    • If you’re going to drive on holiday, take some steps to avoid a hypo. For more information, see: FAQ: Can I drive if I have type 2 diabetes?
    • If you travel a lot, particularly across different time zones, and need more flexibility in how you take insulin, talk to your doctor. They might be able to create a treatment plan that better suits your needs.
    • Ask your doctor to write a letter explaining your need to carry syringes, injection devices, insulin, blood glucose testing equipment, and sharps disposal equipment. You can show this to customs and security at airports.

    For more information about travelling with diabetes, talk to your GP or specialist diabetes clinic.

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  • Reviewed by Rachael Mayfield-Blake, Freelance Health Editor, June 2018
    Expert reviewer, Dr Jonathan Katz, Consultant Endocrinologist
    Next review due June 2021