Diabetes is a condition that causes a person's blood sugar level to become too high.

There are 2 main types of diabetes:

• type 1 diabetes – a lifelong condition where the body's immune system attacks and destroys the cells that produce insulin
• type 2 diabetes – where the body does not produce enough insulin, or the body's cells do not react to insulin properly

Type 2 diabetes is far more common than type 1. In the UK, over 90% of all adults with diabetes have type 2.

High blood sugar that develops during pregnancy is known as gestational diabetes. It usually goes away after giving birth.