Hypoglycemia is a condition in which your blood sugar (glucose) level is lower than normal. Glucose is the body's main energy source. Hypoglycemia is often related to diabetes treatment. But other drugs and a spread of conditions — many rare — can cause low blood glucose in people that do not have diabetes. Hypoglycemia needs immediate treatment when blood glucose levels are low. For many people, a fasting blood glucose of 70 milligrams per deciliter (mg/dL), or 3.9 millimoles per liter (mmol/L), or below should function an alert for hypoglycemia. But your numbers might be different. Ask your doctor. Treatment involves quickly getting your blood glucose back to normal either with high-sugar foods or drinks or with medications. Long-term treatment requires identifying and treating the explanation for hypoglycemia.