Sodium disorders in the emergency department: a review of hypernatremia and hyponatremia.

Manifestation of sodium disorders will depend on the rapidity of development, the absolute level of sodium, and the patient's overall health. Acute symptomatic hypernatremia should be corrected rapidly, while chronic hypernatremia is generally corrected more slowly due to the risks for brain edema during treatment. Hyponatremia symptoms are vague, but acute severe symptomatic hyponatremia, whether self-induced, drug related, or hospital-acquired, is a medical emergency that demands immediate recognition and intervention. This issue reviews the evidence on the causes, diagnosis, and treatment of hypernatremia and hyponatremia in the emergency department, focusing on early recognition and best-practice management.