Hypoglycemia occurs when blood sugar levels drop below 70 milligrams per deciliter (mg/dl). Severe hypoglycemia can be life-threatening if a person does not receive treatment. Treatments focus on returning blood sugar to safe levels. The digestive system breaks down carbohydrates from food. One of the molecules this creates is glucose, the body’s main source of energy. Glucose enters the bloodstream after we eat. However, glucose needs insulin — a hormone that the pancreas produces — before it can enter a cell. In other words, even if there is plenty of glucose available, a cell will starve of energy if there is no insulin. After eating, the pancreas automatically releases the right amount of insulin to move the glucose in blood into the cells. As glucose enters the cells, the blood sugar levels fall. Any extra glucose goes into the liver and muscles in the form of glycogen, or stored glucose. The body can use this glucose later when it needs more energy. Insulin is responsible for bringing high blood sugar levels back to normal.