Diabetes is a lifelong condition that causes a person's blood sugar level to become too high.
The hormone insulin – produced by the pancreas – is responsible for controlling the amount of glucose in the blood
There are two main types of diabetes:
These pages are about type 2 diabetes. Read more about type 1 diabetes.
Another type of diabetes, known as gestational diabetes, occurs in some pregnant women and tends to disappear after birth.
The symptoms of diabetes occur because the lack of insulin means glucose stays in the blood and isn't used as fuel for energy.
Your body tries to reduce blood glucose levels by getting rid of the excess glucose in your urine.
Typical symptoms include:
Read more about the symptoms of type 2 diabetes.
It's very important for diabetes to be diagnosed as soon as possible as it will get progressively worse if left untreated.
Read about how type 2 diabetes is diagnosed.
Type 2 diabetes occurs when the body doesn't produce enough insulin to function properly, or the body's cells don't react to insulin. This means glucose stays in the blood and isn't used as fuel for energy.
Type 2 diabetes is often associated with obesity and tends to be diagnosed in older people. It's far more common than type 1 diabetes.
Type 2 diabetes occurs when the pancreas doesn't produce enough insulin to maintain a normal blood glucose level, or the body is unable to use the insulin that is produced (insulin resistance).
The pancreas is a large gland behind the stomach that produces the hormone insulin. Insulin moves glucose from your blood into your cells, where it's converted into energy.
In type 2 diabetes, there are several reasons why the pancreas doesn't produce enough insulin.
Four of the main risk factors for developing type 2 diabetes are:
These four risk factors are discussed in more detail below.
Read about reducing your risk of type 2 diabetes.
Your risk of developing type 2 diabetes increases with age. This may be because people tend to gain weight and exercise less as they get older.
Maintaining a healthy weight by eating a healthy, balanced diet and exercising regularly are ways of preventing and managing diabetes.
White people over the age of 40 have an increased risk of developing the condition. People of south Asian, Chinese, African-Caribbean and black African descent have an increased risk of developing type 2 diabetes at a much earlier age.
However, despite increasing age being a risk factor for type 2 diabetes, over recent years younger people from all ethnic groups have been developing the condition.
It's also becoming more common for children – as young as seven in some cases – to develop type 2 diabetes.
Genetics is one of the main risk factors for type 2 diabetes. Your risk of developing the condition is increased if you have a close relative such as a parent, brother or sister who has the condition.
The closer the relative, the greater the risk. A child who has a parent with type 2 diabetes has about a one in three chance of also developing the condition.
You're more likely to develop type 2 diabetes if you're overweight or obese with a body mass index (BMI) of 30 or more.
Fat around your tummy (abdomen) particularly increases your risk. This is because it releases chemicals that can upset the body's cardiovascular and metabolic systems.
This increases your risk of developing a number of serious conditions, including coronary heart disease, stroke and some types of cancer.
Measuring your waist is a quick way of assessing your diabetes risk. This is a measure of abdominal obesity, which is a particularly high-risk form of obesity.
Women have a higher risk of developing type 2 diabetes if their waist measures 80cm (31.5 inches) or more.
Asian men with a waist size of 89cm (35 inches) or more have a higher risk, as do white or black men with a waist size of 94cm (37 inches) or more.
Use the BMI calculator to find out if you're a healthy weight for your height.
Exercising regularly and reducing your body weight by about 5% could reduce your risk of getting diabetes by more than 50%.
Read information and advice about losing weight.
People of south Asian, Chinese, African-Caribbean and black African origin are more likely to develop type 2 diabetes.
Type 2 diabetes is up to six times more common in south Asian communities than in the general UK population, and it's three times more common among people of African and African-Caribbean origin.
People of south Asian and African-Caribbean origin also have an increased risk of developing complications of diabetes, such as heart disease, at a younger age than the rest of the population.
Your risk of developing type 2 diabetes is also increased if your blood glucose level is higher than normal, but not yet high enough to be diagnosed with diabetes.
This is sometimes called pre-diabetes, and doctors sometimes call it impaired fasting glycaemia (IFG) or impaired glucose tolerance (IGT).
Pre-diabetes can progress to type 2 diabetes if you don't take preventative steps, such as making lifestyle changes. These include eating healthily, losing weight if you're overweight, and taking plenty of regular exercise.
Women who have had gestational diabetes during pregnancy also have a greater risk of developing diabetes in later life.
As type 2 diabetes usually gets worse, you may eventually need medication – usually tablets – to keep your blood glucose at normal levels.
Treatment for diabetes aims to keep your blood glucose levels as normal as possible and control your symptoms to prevent health problems developing later in life.
If you've been diagnosed with type 2 diabetes, your GP will be able to explain your condition in detail and help you understand your treatment.
They'll also closely monitor your condition to identify any health problems that may occur. If there are any problems, you may be referred to a hospital-based diabetes care team.
If you're diagnosed with type 2 diabetes, you'll need to look after your health very carefully for the rest of your life.
This may seem daunting, but your diabetes care team will be able to give you support and advice about all aspects of your treatment.
After being diagnosed with type 2 diabetes, or if you're at risk of developing the condition, the first step is to look at your diet and lifestyle and make any necessary changes.
Three major areas that you'll need to look closely at are:
You may be able to keep your blood glucose at a safe and healthy level without the need for other types of treatment.
Increasing the amount of fibre in your diet and reducing your sugar and fat intake, particularly saturated fat, can help prevent type 2 diabetes, as well as manage the condition if you already have it.
You should:
The Diabetes UK website has more information and advice about healthy eating.
If you're overweight or obese – you have a body mass index (BMI) of 30 or over – you should lose weight by gradually reducing your calorie intake and becoming more physically active.
Losing 5-10% of your overall body weight over the course of a year is a realistic initial target.
You should aim to continue to lose weight until you've achieved and maintained a BMI within the healthy range, which is:
If you have a BMI of 30kg/m² or more (27.5kg/m² or more for people of south Asian or Chinese origin), you need a structured weight loss programme, which should form part of an intensive lifestyle change programme.
To help you achieve changes in your behaviour, you may be referred to a dietititian or a similar healthcare professional for a personal assessment and tailored advice about diet and physical activity.
Being physically active is very important in preventing or managing type 2 diabetes.
For adults who are 19-64 years of age, the government recommends a minimum of:
An alternative recommendation is to do a minimum of:
Read more about the physical activity guidelines for adults.
In cases where the above activity levels are unrealistic, even small increases in physical activity will be beneficial to your health and act as a basis for future improvements.
Reduce the amount of time spent watching television or sitting in front of a computer. Going for a daily walk – for example, during your lunch break – is a good way of introducing regular physical activity into your schedule.
If you're overweight or obese, you may need to be more physically active to help you lose weight and maintain weight loss.
Your GP, diabetes care team or dietitian can give you more information and advice about losing weight and becoming more physically active.
The Diabetes UK website has more information and advice about getting active and staying active.
Diabetes can cause serious long-term health problems. It's the most common cause of vision loss and blindness in people of working age.
Everyone with diabetes aged 12 or over should be invited to have their eyes screened once a year for diabetic retinopathy.
Diabetes is also responsible for most cases of kidney failure and lower limb amputation, other than accidents.
People with diabetes are up to five times more likely to have cardiovascular disease, such as a stroke, than those without diabetes.
Read more about the complications of type 2 diabetes.
If you're at risk of type 2 diabetes, you may be able to prevent it developing by making lifestyle changes.
These include:
If you already have type 2 diabetes, it may be possible to control your symptoms by making the above changes. This also minimises your risk of developing complications.
Read more about living with type 2 diabetes.