What is Hypoglycemia?

Hypoglycemia, also called low blood glucose or low blood sugar, occurs when blood glucose drops below normal levels. Glucose, an important source of energy for the body, comes from food. Carbohydrates are the main dietary source of glucose.

After a meal, glucose is absorbed into the bloodstream and carried to the body’s cells. Insulin, a hormone made by the pancreas, helps the cells use glucose for energy. If a person takes in more glucose than the body needs at the time, the body stores the extra glucose in the liver and muscles in a form called glycogen. The body can use glycogen for energy between meals. Extra glucose can be changed to fat and stored in fat cells. Fat can also be used for energy.

When blood glucose begins to fall, glucagon – another hormone made by the pancreas – signals the liver to break down the glycogen and release glucose into the bloodstream. Blood glucose will then rise toward a normal level. In some people with diabetes, this glucagons response to hypoglycemia is impaired and other hormones such as epinephrine, also called adrenaline, may raise the blood glucose levels. However, with diabetes treated with insulin or pills that increase insulin production, glucose levels can’t easily return to the normal range.

Hypoglycemia can happen suddenly. It is usually mild and can be treated quickly and easily by eating or drinking a small amount of glucose-rich food. If left untreated, hypoglycemia can get worse and cause confusion, clumsiness, or fainting. Severe hypoglycemia can lead to seizures, coma and even death.