Hypernatremia is most commonly caused by?

Hypernatremia refers to an elevated concentration of sodium in the blood, typically defined as a serum sodium level greater than 145 mEq/L. The most common cause of hypernatremia is dehydration, which can occur when there is a loss of free water in the body. This loss can happen due to various factors, including inadequate fluid intake, excessive sweating, diarrhea, or renal losses.

When the body loses more water than sodium, the sodium concentration in the blood rises. In situations where there is dehydration, the kidneys may also conserve sodium in an attempt to maintain blood volume and pressure, further exacerbating the hypernatremia. It is crucial to recognize that hypernatremia is predominantly a problem of water balance rather than excess sodium intake.

In contrast, excessive salt intake, overhydration, and kidney dysfunction can lead to altered sodium levels, but they are not the primary factors that result in hypernatremia. Excessive salt intake may increase sodium levels, but it typically requires a concurrent loss of water to cause hypernatremia. Overhydration usually leads to dilution of sodium levels, not an increase. Kidney dysfunction can contribute to fluid and electrolyte imbalances, but the direct cause of hypernatremia is