Hypernatremia is characterized by

Hypernatremia is characterized by

• A. Lower-than-normal sodium
• B. Higher-than-normal calcium
• C. Higher-than-normal potassium
• D. Higher-than-normal sodium

Answer: (D)

Hypernatremia means there is more sodium in the blood than usual. Sodium is the main extracellular cation and helps set serum osmolality. When water loss is greater than sodium gain (or water intake is low), the extracellular fluid becomes hyperosmolar, pulling water out of cells and causing cellular dehydration, especially in the brain. That’s why hypernatremia shows up as a higher-than-normal sodium level, typically defined as serum sodium above the upper end of the normal range (roughly >145 mEq/L). Symptoms can include thirst, dry mucous membranes, reduced urine output, and, in severe cases, confusion or seizures due to brain cell dehydration. The other possibilities don’t fit because they involve different ions or states: lower-than-normal sodium describes hyponatremia; higher-than-normal calcium describes hypercalcemia; higher-than-normal potassium describes hyperkalemia.

Hypernatremia means there is more sodium in the blood than usual. Sodium is the main extracellular cation and helps set serum osmolality. When water loss is greater than sodium gain (or water intake is low), the extracellular fluid becomes hyperosmolar, pulling water out of cells and causing cellular dehydration, especially in the brain. That’s why hypernatremia shows up as a higher-than-normal sodium level, typically defined as serum sodium above the upper end of the normal range (roughly >145 mEq/L). Symptoms can include thirst, dry mucous membranes, reduced urine output, and, in severe cases, confusion or seizures due to brain cell dehydration.

The other possibilities don’t fit because they involve different ions or states: lower-than-normal sodium describes hyponatremia; higher-than-normal calcium describes hypercalcemia; higher-than-normal potassium describes hyperkalemia.