The bloodstream carries glucose—a type of sugar produced from the
digestion of carbohydrates and other foods—to provide energy to cells
throughout the body. Unused glucose is stored mainly in the
liver as glycogen.
glucagon, and other hormone levels rise and fall to
keep blood sugar in a normal range. Too little or too much of these hormones
can cause blood sugar levels to fall too low (hypoglycemia) or rise too high
Normally, blood glucose levels increase after you eat a
meal. When blood sugar rises, cells in the
pancreas release insulin, causing the body to absorb
glucose from the blood and lowering the blood sugar level to normal. When blood
sugar drops too low, the level of insulin declines and other cells in the
pancreas release glucagon, which causes the liver to turn stored glycogen back
into glucose and release it into the blood. This brings blood sugar levels back
up to normal.