Hyperglycemia ranges from new onset diabetes to nonketotic hyperglycemia (hyperosmolar hyperglycemic state [HHS]) and diabetic ketoacidosis (DKA). The treatment goals in selected patients with DKA and HHS can be achieved in the observation unit (OU) and include frequent monitoring, IV fluids and insulin to correct hypovolemia, hyperglycemia, hyperosmolality, electrolyte abnormalities and in the case of DKA, correct the metabolic acidosis. For new-onset diabetics, medications can be started and education can be provided. The OU provides an opportunity to address related lifestyle and health issues that affect patient outcomes in diabetes; including diet, exercise, weight loss, and smoking cessation. Patients with elevated lipids can be started on statin therapy and those with established cardiovascular risk factors begin a daily aspirin. An OU stay allows for expedited consultation with endocrinology in select patients with poorly controlled diabetes, which has shown to improve quality of care.