Hypernatremia:

Hypernatremia, or high sodium in the blood, often stems from losing too much water or gaining too much sodium, leading to an imbalance in your body. Symptoms of hypernatremia include excessive... Sodium is a dominant cation in extracellular fluid and is necessary for the maintenance of intravascular volume. The human body maintains sodium and water homeostasis by concentrating the urine secondary to the action of antidiuretic hormone (ADH) and increased fluid intake by a powerful thirst response. These mechanisms to protect against developing hypernatremia are impaired in certain vulnerable populations, vasopressin deficiency, or unresponsiveness at the renal tubular level ... Hypernatremia is an occasionally encountered electrolyte disorder, which may lead to fatal consequences under improper management. Hypernatremia is a disorder of the homeostatic status regarding body water and sodium contents. This imbalance is the basis for the diagnostic approach to hypernatremia. Hypernatraemia is defined as a serum sodium concentration of >145 mmol/L. Most common presentations are the patient in the intensive care unit who is unable to drink water, has a large urine or stool output, and is unable to concentrate urine normally (usually due to renal failure), and the older...