Type 2 diabetes is a lifelong condition in which your body can’t control the level of glucose in your blood. It develops when your body can’t make enough insulin or doesn't respond to it properly.
About 2.9 million people in the UK have been diagnosed with diabetes. There are two main types of diabetes: type 1 and type 2. Type 2 diabetes is the common form, affecting 85 out of every 100 people (including children) with diabetes. You may also hear type 2 diabetes called non-insulin-dependent diabetes and sometimes adult-onset or late-onset diabetes. However, this is misleading as type 2 diabetes is becoming more common in young adults and children.
Type 2 diabetes usually affects people over the age of 40, but can develop at any age. People of African-Caribbean or South Asian origin are more likely to develop the condition. It usually affects them earlier in life, from the age of about 25.
Type 2 diabetes develops when your body can’t produce enough insulin or doesn’t respond to insulin as it should. This happens if your body becomes less sensitive to insulin and doesn’t react to it properly (insulin resistance).
Insulin is important because it regulates the level of glucose in your blood. Glucose is a simple form of sugar found in foods and sugary drinks. It’s absorbed by your body as a natural part of digestion and is carried around your body in your blood. When glucose reaches your body tissues, such as muscle cells, insulin helps it enter the cells where it's converted into energy.
Insulin is produced by your pancreas, which is a gland located behind your stomach. If your pancreas doesn’t produce enough insulin, or your tissue cells don't respond properly to insulin, glucose can build up in your blood. This causes your blood sugar levels to rise.
Many people with type 2 diabetes have no obvious symptoms. It's often discovered during a routine medical check-up with your GP. If you think you may be at risk of type 2 diabetes, speak to your GP. He or she may offer you a screening blood test to check for signs of the condition.
If you do have symptoms of type 2 diabetes, you may:
If you have any of these symptoms, see your GP.
Persistently high blood glucose levels due to uncontrolled diabetes can increase your risk of complications, which can include:
In the long-term, type 2 diabetes can lead to complications even with good control of blood glucose.
If too much sugar builds up in your blood, you may develop hyperglycaemia. This may happen because you missed a dose of insulin or another medicine. You could also develop hyperglycaemia if, you have eaten more carbohydrate than usual or if you have an infection. Symptoms of hyperglycaemia include:
Very rarely, if you have an infection or become dehydrated, your blood glucose can rise to dangerously high levels. This can lead to a condition called hyperosmolar hyperglycaemic state. If this happens, you may become drowsy and lose consciousness. Although the risk of this condition is low, it is a medical emergency and you will need to be treated in hospital.
Your blood glucose levels can become too low (hypoglycaemia) if you don't eat enough carbohydrate while taking insulin or particular medicines called sulphonylureas (eg gliclazide). You’re more likely to develop hypoglycaemia if you take other medicines such as beta-blockers, drink too much alcohol or do more physical activity than usual. Hypoglycaemia can cause you to feel faint, sweaty, confused and you may feel your heart pounding. You can treat it straight away by eating glucose tablets (or a few sweets or a sugary drink), followed by a couple of biscuits or a sandwich.
There are several risk factors that make you more likely to develop type 2 diabetes, including:
Your GP will ask about your symptoms and examine you. He or she may advise you to have a blood test to examine the levels of glucose in your blood. Your GP may also suggest that you have the following tests.
If your blood test results suggest you have type 2 diabetes, your GP may advise you to have repeat tests before your diagnosis is confirmed.
If you're diagnosed with type 2 diabetes, you may be referred to a clinic that has nurses and doctors who specialise in treating diabetes.
There are a number of treatment options for type 2 diabetes, as described below. Which treatments you're offered will depend on your personal circumstances. Your doctor will discuss these with you to help you make a decision that is right for you. Your decision will be based on your doctor’s expert opinion and your own personal values and preferences.
There isn't a cure for type 2 diabetes but it can be controlled. Some people can control their condition with lifestyle changes alone. Others need to take medicines or have insulin injections.
By making the following lifestyle changes, you can help to control your blood glucose levels.
Ask at your clinic whether they run structured education classes. These aim to help you learn how to look after your condition and how to monitor it yourself.
If lifestyle changes alone don’t keep your blood glucose levels under control, your doctor may advise you to take medicines. There are many 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 gets released into your blood from your liver. It also improves the way glucose is used by your muscles. If metformin doesn’t help you reach your desired blood glucose levels within three months, there is a range of medicines that your doctor can offer you instead. The one that you’re offered will depend on many things but some of the possible medicines include the following.
For more information about medicines for type 2 diabetes, speak to your doctor or diabetes specialist nurse.
If lifestyle changes and medicines can’t keep your blood glucose levels under control, your doctor may suggest you have insulin injections.
You will usually inject yourself with insulin once or twice a day, using either a small needle or a pen-type syringe with replaceable cartridges. There are several different types of insulin that work at different rates and for different lengths of time. Ask your doctor for advice on which type is best for you.
If you have insulin injections, you will be advised to monitor your blood glucose levels with a home test kit. This involves taking a pinprick of blood from your finger and putting a drop on a testing strip. A meter will read the result automatically.
Your 'normal' blood glucose range will be specific to you but a general guide for adults with type 2 diabetes is:
Your doctor, GP or diabetes specialist nurse will show you how to monitor your blood glucose levels and tell you how often you need to check it.
Your doctor may advise you to have your levels of HbA1C tested at least once a year. HbA1C is a measure of how well you’re controlling your blood sugar levels over the long term. The test is done by taking blood from a vein in your arm or sometimes a drop of blood from a fingerprick.
You will usually be offered at least one full review of your condition every year.
Reviewed by Pippa Coulter, Bupa Health Information Team, June 2013.
For answers to frequently asked questions on this topic, see FAQs.
For sources and links to further information, see Resources.
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This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.
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