Hypernatremia or hypernatraemia is an elevated sodium level in the blood, specifically a serum level above 145 mEq/L. Hypernatremia is generally not caused by an excess of sodium, but rather by a relative deficit of free water in the body. For this reason, hypernatremia often coincides with dehydration.

Hypernatremia or hypernatraemia is an elevated sodium level in the blood, specifically a serum level above 145 mEq/L. Hypernatremia is generally not caused by an excess of sodium, but rather by a relative deficit of free water in the body. For this reason, hypernatremia often coincides with dehydration.