In hyponatremia, which electrolyte is low?

In hyponatremia, which electrolyte is low?

• A. Sodium
• B. Potassium
• C. Calcium
• D. Magnesium

Answer: (A)

Hyponatremia is defined by a low concentration of sodium in the blood. Sodium is the primary extracellular cation and helps regulate total body water, maintaining the balance of fluids between compartments. When sodium levels fall, water can move into cells, including brain cells, which can lead to swelling and neurologic symptoms such as confusion, seizures, or even coma if severe. Because hyponatremia centers on decreased sodium, the electrolyte that is low is sodium. Potassium, calcium, and magnesium are different electrolytes with their own normal ranges and clinical implications. They can be affected in various conditions, but hyponatremia itself specifically refers to a low sodium level.

Hyponatremia is defined by a low concentration of sodium in the blood. Sodium is the primary extracellular cation and helps regulate total body water, maintaining the balance of fluids between compartments. When sodium levels fall, water can move into cells, including brain cells, which can lead to swelling and neurologic symptoms such as confusion, seizures, or even coma if severe. Because hyponatremia centers on decreased sodium, the electrolyte that is low is sodium.

Potassium, calcium, and magnesium are different electrolytes with their own normal ranges and clinical implications. They can be affected in various conditions, but hyponatremia itself specifically refers to a low sodium level.