Hypernatremia is a relatively common entity and is more prevalent among the elderly and critically ill. A number of medical conditions are commonly associated with hypernatremia, and these differ substantially among children and adults. Severe hypernatremia is usually associated with central nervous system manifestations and carries a high mortality rate. We report a case of a female patient who presented to the emergency department of the King Khalid University Hospital, Riyadh, Saudi Arabia with severe hypernatremia and without any associated co-morbid conditions or neurological manifestations. We did not find any etiological background despite extensive evaluation other than under hydration due to decreased fluid intake, which was secondary to behavioural causes.