Sugar is the basic fuel for the cells in your body. This section will help you understand how sugar works and doesn't work in the body, starting with the pancreas — the organ most commonly associated with diabetes.
What does the pancreas do?
The pancreas is a digestive gland found behind the lower part of the stomach. It is about 8 inches (22 cm) long, and keeps your body healthy by producing enzymes and hormones. The most important of these is insulin, which regulates blood sugar.
How does insulin control blood sugar?
After digestion, sugars broken down from food (also called "glucose") enter the bloodstream where they can be absorbed by the body's tissue (i.e., muscles and organs) for use as fuel. Insulin's job inside the body is to enable this process by helping sugar leave the bloodstream and enter the cells that need fuel.
Why does my body need to control my blood sugar?
Your body, especially your brain, needs sugar as its fuel. If there is too little sugar in the blood, your cells are starved for energy. The symptoms of this condition (also called "hypoglycemia") include tiredness and disorientation similar to intoxication. If the amount of sugar in the blood becomes extremely low, a coma can occur.
On the other hand, if there is too much sugar in the blood stream (also called "hyperglycemia"), it's a sign that the body hasn't been able to convert that sugar into energy. The unused sugar accumulates in the blood and then passes through the kidneys, causing frequent urination and thirst (the body's way of making up for fluid lost in urination).
If the body continues to buildup sugar in the bloodstream, it tries to find another energy source — fat. The process of breaking down fat into energy has by-products called "ketones." Excess sugar and ketones in the blood are toxic. Symptoms of this condition (called "ketoacidosis") include nausea, headache, drowsiness and "fruity-smelling" breath. This is a very serious condition that can end in a coma or death.
What makes diabetes harmful?
If your blood sugar remains high for extended periods, the resulting disease is called diabetes mellitus. As explained above, high blood sugar means your body hasn't been able to use sugar as fuel. The reason for this "system malfunction" is a lack of insulin. Without the insulin to make sugar leave the bloodstream, there is a build up of sugar as your cells starve and your blood becomes toxic. Cells and tissue are destroyed, eventually damaging the kidneys, eyes, heart, blood vessels and nerves. These short- and long-term effects are the reason treatment is so important. A controlled diet, drugs, insulin injections or pump therapy can significantly reduce complications.