Increased extracellular fluid osmotic pressure

Increased extracellular fluid osmotic pressure is a clinical manifestation of hypertonic dehydration. Hypertonic dehydration refers to the simultaneous loss of water and sodium, but more water than sodium, so serum sodium is higher than the normal range, and extracellular fluid is hypertonic. When there is more water than sodium, the osmotic pressure of extracellular fluid increases, the secretion of antidiuretic hormone increases, the reabsorption of water by the renal tubules increases, and the urine output decreases. Aldosterone secretion increases and sodium and water reabsorption increases to maintain blood volume. If the dehydration continues, the osmotic pressure of the extracellular fluid will further increase, the intracellular fluid will move out of the cell, and finally the intracellular fluid dehydration will exceed the extracellular fluid dehydration. Dehydration of brain cells will cause brain dysfunction.