In people with diabetes, low blood sugar (hypoglycemia) can be caused by a lack of carbohydrates, exercising without eating, incorrect medication dosage, not following a medication schedule, drinking alcohol, weight loss, and kidney disease. For people without diabetes, hypoglycemia can be caused by certain medications, too much alcohol, hormonal deficiency, insulin autoimmune syndrome, overproduction of insulin, kidney disorders, severe hepatitis, and more.