Whilst both type 1 and type 2 diabetes are characterised by having higher than normal blood glucose levels, the cause and development of the conditions are different. About 90% of people with diabetes have type 2, 8% have type 1 and about 2% have rarer types.

Diabetes mellitus is a significant global burden for health care. There are approximately 537 million people worldwide living with diabetes and, in the UK, around 6.3% of the adult population, aged between 20 – 79 have the condition (International Diabetes Federation (IDF) Atlas 2021). Across the UK there are over 3.8 million people with a diagnosis of diabetes mellitus and an estimated one million people who have the condition, but don’t know it (Diabetes UK, 2019 Facts and Stats). This represents approximately 9% of the UK population.

Type 1 diabetes is an autoimmune disease, which develops when the insulin-producing cells in the body are destroyed, and the body is unable to produce insulin. It is unclear why this happens, but the most likely reason is that the body has an abnormal reaction to the pancreatic beta cells which produce insulin and begins to destroy them. This could be triggered by an infection or virus but again this is not known for sure. It can develop at any age but usually appears before the age of 40, and especially in childhood. A person with type 1 diabetes will need to take insulin injections or use an insulin pump for life. They will also need to ensure that their blood glucose level stays balanced by eating a healthy diet, take regular physical activity and carry out regular blood glucose testing.

What causes type 2 diabetes?

Type 2 diabetes develops when the body can still produce some insulin but not enough for energy from glucose to be utilised properly, or when the cells in the body do not react properly to insulin. This is called insulin resistance. 

How is type 2 diabetes managed?

The treatment of type 2 diabetes centres on lifestyle management including a healthy diet, regular exercise and the person monitoring their blood glucose level. The condition may progress over time and a number of oral glucose therapies are also used, with or without additional insulin injections and Incretin mimetics / GLP-1 analogues. Some medications help the body to use insulin more effectively whilst others increase the amount of insulin that the body produces.

Type 2 diabetes is often associated with obesity, and is also increasingly becoming more common in children, adolescents and young people of all ethnicities. Type 2 diabetes is far more common than type 1 diabetes - around 90% of all adults in the UK with diabetes have type 2 diabetes.

Type 2 diabetes risk factors include:

• carrying too much excess body fat – especially central body fat
• having high blood pressure or cholesterol
• genetics: having a close family member with type 2 diabetes (mother, father, brother or sister)
• having previously had gestational diabetes
• drugs such as steroids and anti-depressants
• ethnicity: common in Asian and Afro-Caribbean.

Further Resources

Diabetes UK. Diabetes risk factors