blood test

Diabetes is a lifelong condition that causes a person's blood sugar level to become too high.

There are two main types of diabetes – type 1 diabetes and type 2 diabetes. In 2010, there were approximately 3.1 million people aged 16 or over with diabetes (both diagnosed and undiagnosed) in England. By 2030, this figure is expected to rise to 4.6 million, with 90% of those affected having type 2 diabetes.

The charity Diabetes UK estimates that around 850,000 people in England have diabetes but haven't been diagnosed. Many more people have blood sugar levels above the normal range, but not high enough to be diagnosed as having diabetes. This is sometimes known as prediabetes. If your blood sugar level is above the normal range, your risk of developing full-blown diabetes is increased. It's very important for diabetes to be diagnosed as early as possible because it will get progressively worse if left untreated.

You should therefore visit your GP as soon as possible if you have symptoms, such as feeling thirsty, passing urine more often than usual, and feeling tired all the time.

Symptoms of diabetes

The main symptoms of diabetes are:

  • feeling very thirsty
  • urinating more frequently than usual, particularly at night
  • feeling very tired
  • weight loss and loss of muscle bulk
  • itching around the penis or vagina, or frequent episodes of thrush
  • cuts or wounds that heal slowly
  • blurred vision (caused by the lens of the eye becoming dry)

Type 1 diabetes can develop quickly over weeks or even days.

Many people have type 2 diabetes for years without realising because the early symptoms tend to be general.

What causes diabetes?

The amount of sugar in the blood is controlled by a hormone called insulin, which is produced by the pancreas (a gland behind the stomach).

When food is digested and enters your bloodstream, insulin moves glucose out of the blood and into cells, where it's broken down to produce energy.

However, if you have diabetes, your body is unable to break down glucose into energy. This is because there's either not enough insulin to move the glucose, or the insulin produced doesn't work properly.

Type 1 diabetes

Read more about type 1 diabetes and living with diabetes.

Type 2 diabetes

Read more about type 2 diabetes.

Diabetic eye screening

Gestational diabetes (in pregnancy)

Read more about gestational diabetes.

Further Information

Diabetes, Driving and the Law

If you have diabetes and wish to drive, it is important to know the law and how it affects you. This will help to keep you as safe as possible, as well as making sure you aren't prosecuted for illegal driving. This section will help explain your rights and responsibilities as a driver with diabetes.

Do you need to inform the Driving and Vehicle Licensing Agency (DVLA)?

If you have a driving licence, it is probably for Group 1 vehicles i.e the usual licence for cars and some types of motorcycle that most people hold. If this is the case, you do not automatically inform the DVLA if your diabetes is treated by diet alone or by diet, tablets and/or non-insulin injections (e.g. exenatide).

However the law requires you to inform the DVLA as soon as possible if:

Safe Driving measures


Licence to drive large vehicles such as buses or lorries

If you are treated with non-insulin medication that may cause Hypoglycaemia

If you are treated with insulin

If you can meet all the above requirements there are then three stages in the application process for a Group 2 licence:

First Stage

Second Stage

Third Stage

Annual Assessment once a Group 2 licence has been granted

Further Information

Diabetes and Travel

preparing to travel 

While you are away: