Because it does not have to be broken down in the lower digestive system, it passes directly into the bloodstream from the small intestine and is stored as glycogen in the liver. Glucose is classified as a carbohydrate and is found in most sugars and starches. The amount of glucose in the blood is called the blood sugar content, which is carefully regulated by the pancreatic hormone insulin and, to a lesser extent, by other hormones.
Insufficient insulin produces high blood sugar, as in diabetes mellitus.
Glucose preparations are used in the treatment of dehydration and other disorders. Low blood sugar, hypoglycemia, is associated with Addison's disease, insulin shock, hypopituitarism, and myxedema, a severe form of hypothyroidism.