Snapshot A 79-year-old woman is brought to the emergency department from home for altered mental status. Her family reports that she is normally alert and oriented to person, place, and time, and very conversational. On exam, she is confused, alert only to person, and appears anxious. She has moist mucous membranes and normal skin turgor. Pulmonary auscultation reveals localized crackles. Laboratory tests are significant for serum sodium of 126 mEq/L. Introduction Clinical definition login to view 1 more bullet Epidemiology Demographics login to view 1 more bullet Risk factors login to view 5 more bullets etiology Ectopic production login to view 1 more bullet Central nervous system disorders login to view 5 more bullets Drugs login to view 5 more bullets Pathogenesis login to view 4 more bullets Presentation Symptoms login to view 11 more bullets Physical exam login to view 3 more bullets Studies Diagnostic testing login to view 10 more bullets Differential Other causes of euvolemic hyponatremia login to view 7 more bullets Treatment Management approach login to view 5 more bullets First-line login to view 10 more bullets Second-line login to view 3 more bullets Other medications login to view 2 more bullets Complications Osmotic demyelination syndrome (central pontine myelinolysis) login to view 1 more bullet