This section of the website is for UK healthcare professionals only. If you are not a healthcare professional, please click here.
This section of the website is for UK healthcare professionals only. If you are not a healthcare professional, please click here.

This section of the website is for members of the public. If you are a healthcare professional,visit the HCP section of the site. This website is not intended to replace the advice of a healthcare professional. You should consult your doctor or another suitably trained healthcare provider when considering what type of treatment is most appropriate for you.


What is diabetes?

Diabetes or diabetes mellitus is a chronic disease characterised by the body's inability to control blood sugar (glucose). This leads to a state of high blood sugar or hyperglycaemia, which can damage the organs of the body over time if it is not treated.

There are two main types of diabetes - type 1 and type 2.

Type 1 diabetes

Type 1 diabetes affects around 5-15% of people with diabetes mellitus. It can occur at any age but it is often diagnosed in children and usually develops before 40 years of age.

This type of diabetes is caused by the body's inability to produce any insulin to help control blood sugar. The insulin needed to keep blood sugar under control therefore needs to be replaced by daily injection. As a result, this type of diabetes used to be called insulin-dependent diabetes mellitus (IDDM)

In addition to insulin injections, the treatment of type 1 diabetes involves eating a healthy diet and undertaking regular physical activity.

Type 2 diabetes

Type 2 diabetes is the most common form of the disease. It affects 90% of all people with diabetes mellitus. It usually occurs in people aged 40 years or older, but it can affect younger adults, as well as children and adolescents.

People with this type of diabetes are usually still able to produce insulin to help control blood sugar, but there may be too little insulin or the body's cells may not respond sufficiently to the effects of insulin, a condition known as insulin resistance.

As the body can usually make insulin, medications used to treat type 2 diabetes often try to stimulate the release of insulin in the body or increase the body's sensitivity to the effects of insulin. These medications are used in combination with eating a healthy diet and undertaking regular physical activity.

This type of diabetes used to be called non-insulin-dependent diabetes mellitus (NIDDM) because it was not thought to require insulin injections. This is not always the case, however, and while dietary management and oral medicines may help to control blood sugar, some people may need insulin therapy.

Signs and symptoms of diabetes

Three common signs and symptoms of undiagnosed diabetes mellitus include:

  • Increased thirst (polydipsia)
  • Increased urination (polyuria)
  • Slow healing of cuts and wounds

People with undiagnosed diabetes may also experience:

  • Extreme tiredness
  • Weight loss that cannot be otherwise explained
  • Recurrent episodes of thrush (candidiasis)
  • Blurred vision

People with type 1 diabetes may exhibit very obvious signs and symptoms of diabetes, typically over a period of a few weeks. In contrast, signs and symptoms of diabetes in people with type 2 diabetes may develop over a period of years and may not be obvious until they are noticed at a routine medical check up.

Further information about diabetes

Find out more about diabetes at www.diabetes.org.uk - the website for Diabetes UK.

Diabetes UK is the UK's leading diabetes charity that cares for, connects with and campaigns on behalf of every person affected by or at risk of diabetes.