Explain how type 1 diabetes occurs

Type 1 diabetes occurs when the immune system to fails to identify a group of cells in the pancreas called the beta islet of Langerhans cells as 'self' cells. This means that they are recognised as 'foreign' and destroyed early on in life. These are the cells that would normally produce insulin in a healthy individual. Therefore, people with type 1 diabetes can't produce insulin and so they can't regulate their own blood sugar levels.