Patient Information

What is Diabetes?

Diabetes is a common life-long health condition. There are 2.8 million people diagnosed with diabetes in the UK and an estimated 850,000 people who have the condition but don’t know it. (Latest information from Diabetes UK)

Diabetes is a condition where the amount of glucose in your blood is too high because the body cannot use it properly. This is because your pancreas does not produce any insulin, or not enough, to help the glucose enter your body’s cells – or the insulin that is produced does not work properly (this is known as insulin resistance).

Insulin is a hormone produced by the pancreas that allows glucose to enter the body’s cells, where the glucose is used as fuel for energy so we can live our lives.

Glucose comes from the food we eat. When we eat a carbohydrate food it breaks down into glucose; glucose is also produced by the liver. Carbohydrate comes from many different kinds of foods and drink, including starchy foods such as bread, potatoes and chapatis, fruit, some dairy products, sugar and other sweet foods. If you have diabetes, your body is unable to use glucose properly so it builds up in the blood and isn’t used as fuel.

Type 1

Type 1 diabetes develops when the insulin-producing cells in the body have been destroyed and the body is unable to produce any insulin. Insulin mis often describes as the key that unlocks the door to the body’s cells. Once the door is unlocked, glucose can enter the cells where it is used as fuel for energy.

In type 1 diabetes, the body is unable to produce any insulin so there is no key to unlock the door and the glucose builds up in the blood. Nobody knows why these insulin-producing cells have been destroyed but the most likely cause is the body having an abnormal reaction to the cells. This may be triggered by a virus or other infection. Type 1 diabetes can develop at any age but usually appears before the age of 40, and especially in childhood.

Type 1 diabetes accounts for between 5 and 15 per cent of all people
with diabetes and is treated by daily insulin injections (or infusion through an insulin pump), a healthy diet and regular physical activity.

Type 2

Type 2 diabetes develops when the body can still make some insulin, but not enough, or when the insulin that is produced does not work properly (known as insulin resistance). Insulin as stated before acts as a key unlocking the cells, so if there is not enough insulin, or it is not working properly, the cells are only partially unlocked (or not at all) and glucose builds up in the blood.

Type 2 diabetes usually appears in people over the age of 40. It is, however, becoming more common in children, adolescents and young people of all ethnicities. Type 2 diabetes accounts for between 85 and 95 per cent of all people with diabetes and is treated with a healthy diet and increased physical activity. In addition to this, medication and/or insulin is often required.

*The information on this page has been reproduced from with kind permission of Diabetes UK. © Diabetes UK

Block A Level One, Queen Mary's Hospital, Frognal Avenue, Sidcup, Kent, DA14 6LT Diabetes Queries: 020 8269 3419