The human body is a machine that can heal itself, reproduce, make independent choices, and involuntarily regulate hormones and chemicals that modern technology has a hard time regulating. One of these hormones which is crucial to the survival and maintenance of one's physical body is insulin, produced by the pancreas, located just above the stomach. Insulin allows carbohydrates ingested to be turned into energy within the bloodstream, where nutrients from food get absorbed into. Without insulin we have no way of converting things we eat into energy except our own body. Too much insulin in the blood stream is called hypoglycemia. This means that there is more insulin than needed for the amount of glucose, the simplest type of sugar which carbohydrates come from, in the blood. The opposite, hyperglycemia, is when there is too much glucose in the blood stream and not enough insulin on board to turn it into energy. I always like to equate this to drinking Drano, because in effect what one is doing by eating food and not taking insulin for it is just flushing food through the body, not benefiting at all from the things it leaves behind. If a diabetic neglects to take care of oneself and not take insulin, the body will not be getting the nutrients it needs from the food being taken in. Its only alternative is to eat itself; the proteins and vitamins that are needed are stored in muscles and fat. Shortly before this reserve is taken up, many things can happen such as blindness, kidney disease, the amputation of a limb, and many other bad side effects can occur.
There are mainly three types of diabetes, two of them being the most common. Those two have "special scientific" names for them: Type 1 and type 2 diabetes. The other is called gestational, which is a temporary onset of diabetes during pregnancy, effecting only four percent of pregnant woman. Type 2 diabetes is the most common, accounting for 90 to 95 percent of diabetes cases.