Hypoglycemia is the medical term for a low level of blood glucose or low blood sugar. Normally, hypoglycemia is corrected by a release of the chemical glucagon, which in turn causes glycogen in the liver to be broken down into glucose to bring blood sugar back to normal. However, in diabetics, this response by glucagon is not as effective and other chemicals, such as epinephrine are used by the body to balance blood sugar levels.