Extreme Hypernatremia due to Dehydration.

Hypernatremia is defined as having a serum sodium concentration exceeding 145 mmol/L (normal range is 136 - 145 mmol/L). When the serum sodium level surpasses 160 mmol/L and 190 mmol/L, it is classified as severe and extreme hypernatremia, respectively. Extreme hypernatremia is an uncommon occurrence and is associated with significant risks of mortality and morbidity. The most frequently reported causes of extreme hypernatremia are accidental or intentional salt ingestion and diabetes insipidus, while dehydration due to poor water intake as a trigger for extreme hypernatremia is rarely documented. Here, we present a case study of an elderly patient who experienced extreme hypernatremia with a serum sodium level of 191 mmol/L due to dehydration and had altered mental status and ventriculomegaly as a complication.