Diabetes is a lifelong condition that causes a person's blood sugar level to become too high.
There are 2 main types of diabetes:
Type 1 diabetes – 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
Type 2 diabetes is far more common than type 1. In the UK, around 90% of all adults with diabetes have type 2.
During pregnancy, some women have such high levels of blood glucose that their body is unable to produce enough insulin to absorb it all. This is known as gestational diabetes.