Glucose is a carbohydrate and natural simple sugar that is found in plant and animal products. It is the major source of energy for most of the cells in the body, making it the most important simple sugar to the human metabolism.  Glucose is a natural product of photosynthesis in plants and is created during the breakdown of glycogen in animals and fungi. It can be commercially produced as well. Individuals with diabetes suffer from metabolic diseases in which there are high blood sugar levels over a prolonged period. Adversely, those with hypoglycemia suffer from low blood sugar levels.