The Islet cells produced insulin. So now unfortunately no insulin is produced. A slight problem... Without insulin you die a slow death of wasting away--basically starving to death.
Insulin is usually defined as the key that lets glucose or "sugar" to enter the cells and be used for energy. The sugar enters the blood from the digestive system from the foods you eat. Either straight sugar or when starches are broken down. Your body also and use other foods as sources of energy-like fat.
I like to think of insulin as more of a glucose posse. It actually rounds up the sugar and takes it off into the cells and causes the level of sugar in the blood to drop. Normally you eat something, your body digests it, the level of sugar in the blood begins to rise, the body releases extra insulin into the gut and this causes the sugar to be taken rather forcefully into the cells. So now I'm missing a crucial part. Without the insulin the cells can't use sugar and the sugar level in the blood begins to rise. Your body begins to think it is starving (which it is) and begins to break fat down into sugar. If you have an excess of fat you may build up ketones from the breakdown of the fats and develop ketoacidosis.
Meanwhile, your sugar levels are getting higher and higher. Your kidneys try to lower the high levels of glucose (which is, in itself a toxic substance to your body at high levels) by producing more urine. This causes one to urinate constantly and therefore become quite dehydrated--classic diabetes symptoms.
So the person with diabetes must take insulin injections often and try as well as possible to simulate the action of a functioning pancreas.
Next post.... What it feels like to wake up and not know where you're at (And not from drinking heavily) and how treatment works in with an athletic lifestyle.