A common problem

Diabetes occurs because the body can't use glucose properly, either owing to a lack of the hormone insulin, or because the insulin available doesn't work effectively.

The full name 'diabetes mellitus' derives from the Greek word 'diabetes' meaning siphon - to pass through - and 'mellitus' - the Latin for honeyed or sweet. This is because not only is excess sugar found in the blood but it may also appear in the urine, hence it being known in the 17th century as the 'pissing evil'.

Diabetes has been a recognised condition for more than 3,500 years.

According to the charity Diabetes UK, more than 2 million people in the UK have the condition, and up to 750,000 more are believed to have it without realising they do.

More than three-quarters of people with diabetes have what is called type 2 diabetes mellitus.This used to be known as non-insulin dependent diabetes mellitus (NIDDM) or maturity-onset diabetes mellitus.

The remainder have type 1 diabetes mellitus, which used to be known as insulin-dependent diabetes mellitus.

What's the difference?

In type 1, the body's unable to produce any insulin. This usually starts in childhood or young adulthood. It's treated with diet control and insulin injections.

In type 2, not enough insulin is produced or the insulin that is made by the body doesn't work properly. This tends to affect people as they get older, and usually appears after the age of 40.