Diabetes risk calculator

Description of the tool

The Glucose on Unselected Admission and Risk of Diabetes (GUARD) risk calculator is designed to identify people at increased risk of type 2 diabetes. It can be used in people who have been admitted to hospital for a medical or surgical emergency, and who have had a blood glucose measured during their acute illness.

Why this risk calculator is needed

It is very common for people admitted to hospital to have their glucose measured. Among those tested, it is very common to find a high glucose result. Normally, the presence of a very high glucose measurement means that someone has diabetes. However, glucose measurements taken during acute illnesses can't be used as evidence that a person has diabetes. This is because an acute illness can cause a high glucose reading even in someone without diabetes.

The purpose of the GUARD risk calculator is to allow a doctor or nurse to decide whether a person who has a raised glucose during an acute illness needs further testing for diabetes. Such further testing would usually be in the form of a blood test when the person has recovered from their acute illness.

If your doctor or nurse uses the GUARD tool then they will share your risk of diabetes with you and, if it is necessary, will arrange for you to have follow-up testing.


People who have not recently been admitted to hospital

The GUARD tool is only for patients with an acute illness. Glucose results measured in people without an acute illness can be interpreted in the usual way to determine whether or not someone has diabetes based on criteria agreed by the World Health Organisation .

It is not practical or worthwhile for everyone to have a blood test for diabetes. Therefore, a number of tools have been developed to identify people in the community who are at increased risk of type 2 diabetes, whether or not they have had a recent acute illness. One such tool developed by the University of Leicester is available below

Further information

Riskscore tool from University of Leicester

Diagnostic criteria for diabetes


The following websites provide information on the symptoms, diagnosis and treatment of type 2 diabetes.

Diabetes UK

NHS CHoices