Diabetes occurs when your blood glucose, also called blood sugar, is too high. In type 1 diabetes, the body’s immune system, which normally fights infection, attacks, and destroys the cells in the pancreas that make insulin. As a result, glucose can’t get into the cells and blood glucose rises above normal. People with type 1 diabetes need to take over the function of the pancreas, which includes taking insulin multiple times a day via injections or insulin pump, in order to maintain blood glucose in as close to a normal range as possible. Hypoglycemia (low blood sugar) and hyperglycemia (high blood sugar) are both common in type 1 diabetes and can occur if too little or too much insulin is administered. Both extremely low and high blood glucose can be dangerous, both in the short and long term.