Identifying and correcting sodium abnormalities is critical, since suboptimal management potentially leads to substantial morbidity and mortality. Manifestations of hyponatremia, which is one of the more common electrolyte abnormalities in clinical medicine, depend on multiple factors, including the chronicity of the symptoms, the absolute level of sodium, and the patient's overall health. In symptomatic hyponatremia, emergency clinicians must understand the importance of determining the proper rate of sodium correction in order to avoid encephalopathy, cerebral edema, and death. Hypernatremia is most often due to unreplaced water that is lost from the gastrointestinal tract, skin, or the urine. Acute symptomatic hypernatremia should be corrected rapidly, while chronic hypernatremia is generally corrected more slowly due to the risks of brain edema during treatment. Special circumstances do exist in sodium management, and every patient's presentation should be evaluated in clinical context.