The National Institute of Diabetes and Digestive and Kidney Diseases Glucose, a form of sugar, is the body's main fuel. Hypoglycemia, or low blood sugar, occurs when blood levels of glucose drop too low to fuel the body's activity.
Unused glucose is stored in the liver as glycogen.
Hypoglycemia can occur as a complication of diabetes, as a condition in itself, or in association with other disorders. This can be seen in healthy women, particularly after prolonged fasting. The amount of glucose in the blood is controlled mainly by the hormones insulin and glucagon. The pancreas, a gland in the upper abdomen, produces insulin and glucagon. The pancreas is dotted with hormone-producing tissue called the islets of Langerhans, which contain alpha and beta cells.