Abstract
Abstract: Sodium and chloride are primarily responsible for fluid movement across the compartments of the body. Neurologic, hormonal, and renal factors combine to regulate sodium levels and preserve fluid volume homeostasis. This article covers the causes, signs and symptoms, and available treatments for the following sodium and chloride imbalances associated with morbidity and mortality in critically ill patients: hyponatremia, hypernatremia, hyperchloremia, and hypochloremia.