Diabetes (diabetes mellitus to give it its full name) is a lifelong condition in which the amount of glucose (sugar) in the blood is too high because the body's way of converting glucose into energy is not working as it should.

Our bodies need glucose for energy. Glucose enters the bloodstream when you digest carbohydrate from food and drink, including starchy foods (such as bread, rice, and potatoes), fruit, some dairy products, sugar and other sweet foods. Glucose is also produced by the liver.

In people without diabetes, a hormone (a chemical messenger) called insulin carefully controls the amount of glucose in the blood. Insulin is made by a gland called the pancreas, which lies just behind the stomach. It acts as the ‘key' that ‘unlocks' the body's cells to let the glucose in and convert it to energy.

In a person with diabetes, the body either does not produce insulin at all (type 1) or it does not produce enough insulin or the insulin it does produce does not work very well (type 2).

In this section, you'll find information about:  

Type 1 diabetes

Type 1 diabetes is when no insulin is produced at all because the insulin-producing cells in the pancreas have been destroyed. Nobody knows for sure why these cells have been damaged but the most likely cause is the body having an abnormal reaction to the cells. There is nothing that you can do to prevent type 1 diabetes. This type of diabetes is always treated with insulin injections.

Oxleas Specialist Diabetes Team work with people with type 2 diabetes in the Royal Borough of Greenwich. The information on this site relates to type 2 diabetes. Please see the NHS website or Diabetes UK for more information about type 1 diabetes.

Type 2 diabetes

Type 2 diabetes is when the body either does not produce enough insulin, or the insulin it produces does not work as well as it should (insulin resistance). This type of diabetes is treated with lifestyle changes, following a healthy balanced diet, increasing physical activity and losing weight if you need to. Some people may also need medications and/or insulin injections to achieve normal blood glucose levels.

Unlike type 1 diabetes, type 2 diabetes can be attributed to a number of factors. Some are out of your control while others, such as being overweight, you can act on to reduce the risk of developing diabetes. See causes and symptoms for more information.

Diabetes is a metabolic disorder (a disorder affecting the normal chemical processes in the body) or a polygenic disease (a genetic disorder caused by the combined action of more than one gene) due to the extremely high glucose levels in the blood. The prevalence of diabetes in the UK is increasing year on year.