Disorders of sodium imbalance are commonly encountered in clinical practice and can have a substantial impact on the prognosis of the patient. These disorders are more common in the elderly. Sodium disorders can cause serious neurologic symptoms and even death, particularly among hospitalized patients. The identification of sodium abnormalities and appropriate clinical intervention are critical for improving patient outcomes. Early recognition of hyponatremia and hypernatremia can provide a clue to an underlying disorder. In this update, we have summarized age-related homeostatic changes that impair sodium balance, medications that alter salt and water handling, and the recognition and management of sodium disorders in elderly patients.