Which symptoms arise from hypernatremia?

Hypernatremia refers to an elevated sodium concentration in the blood, typically defined as a serum sodium level greater than 145 mEq/L. This condition often arises from water loss or sodium retention but is primarily characterized by a deficit of water relative to sodium.

One of the hallmark symptoms of hypernatremia is central nervous system (CNS) dysfunction. This can manifest in various forms, starting with mild symptoms like confusion and irritability, but can progress to more severe impairments such as seizures, coma, or even death in extreme cases. These neurological manifestations are directly related to the hyperosmolar state created by elevated sodium levels, which leads to water moving out of neurons, causing cellular dehydration and dysfunction.

While dehydration, increased thirst, and nausea can occur in hypernatremia, especially due to its effects on water balance and the body's compensatory mechanisms, they are not as defining or critical features of the condition as CNS dysfunction. CNS symptoms reflect the most significant and emergent complications of hypernatremia, making them the most pertinent in the context of this question. Understanding the severe implications of CNS dysfunction is crucial in managing hypernatremia effectively, as immediate intervention may be necessary to prevent irreversible brain injury.