Hypoglycemia is a common adverse event in patients with both type 1 and type 2 diabetes and may be a barrier to patients achieving tight glycemic control. It is diagnosed either biochemically, as a blood glucose value, or clinically based on symptoms caused by an autonomic response to changes in blood glucose. Patients that experience repeated episodes of hypoglycemia lose the counterregulatory response that produces symptoms and results in hypoglycemia unawareness. Medications account for the most frequent cause of hypoglycemia in both the inpatient and outpatient setting. Treatment of hypoglycemia may be accomplished via the oral or parenteral route with 15 to 20 g of carbohydrate. Following treatment of the episode, it is important to evaluate for the cause and, if medication related, adjust the patient’s treatment regimen.