Hyponatremia in the elderly

The normal value of blood sodium is 142mmol / L (135 ～ 145mmol / L), and the blood sodium is less than 135mmol / L, which is hyponatremia. Hyponatremia is a common electrolyte disorder in clinical practice. Sodium and water are closely related and interdependent. The blood sodium concentration is reduced, and the osmotic pressure of plasma is also generally reduced. Therefore, hyponatremia is also called hyponatremia hypotonic syndrome. It should be clearly determined that the measured plasma sodium concentration does not explain the total amount of sodium in the body and the distribution of sodium in the body, and a decrease in the measured sodium concentration in the plasma does not necessarily determine the sodium deficiency in the body. Such as dilute hyponatremia, the total amount of sodium in the body does not decrease, and sometimes even increases, but because the increase of water in its overall fluid is more obvious than the increase of sodium, the plasma sodium concentration is reduced. .