Diabetes is a lifelong condition that causes a person's blood sugar level to become too high.
There are two main types of diabetes, referred to as type 1 and type 2.
Type 1 diabetes is often referred to as insulin-dependent diabetes. It is also sometimes known as juvenile diabetes or early-onset diabetes because it often develops before the age of 40, usually during the teenage years.
In type 1 diabetes, the pancreas (a small gland behind the stomach) does not produce any insulin. Insulin is a hormone that regulates blood glucose levels. If the amount of glucose in the blood is too high, it can seriously damage the body's organs.
If you have type 1 diabetes, you will need to take insulin injections for life. You must also make sure that your blood glucose levels stay balanced by eating a healthy diet, taking regular exercise and having regular blood tests.
Type 2 diabetes occurs when the body doesn't produce enough insulin to function properly, or the body’s cells don't react to insulin. This is known as insulin resistance.
Type 2 diabetes is far more common than type 1 diabetes, which occurs when the body doesn't produce any insulin at all. Type 2 diabetes usually affects people over the age of 40, although increasingly younger people are also being affected. It is more common in people of South Asian, African-Caribbean or Middle Eastern descent.
Source: NHS choices