Hyponatremia content leads to hypervolemia and water content to hyponatremia. There is volume expansion in the body, no edema, but hyponatremia occurs Hypovolemia (extracellular volume loss) is due to total body sodium loss. Hyponatremia is caused by a relatively smaller loss in total body water. Miscellaneous causes that are not included under the above classification scheme include the following: The causes of and treatments for hyponatremia can only be understood by having a grasp of the size of the body fluid compartments and subcompartments and their regulation; how under normal circumstances the body is able to maintain the sodium concentration within
Hypotonic hyponatremia blood volume that is no longer there, that has been lost from the body. As a result, their blood volume is reduced. As mentioned above, lack of adequate blood volume is a potent stimulus for ADH secretion and thence water retention. Some patients with hyponatremia have normal or slightly elevated blood volume. In those patients, the increased ADH activity and subsequent water retention may be due to "physiologic" causes of ADH release such as pain or nausea. Alternatively, they may have the Syndrome of Inappropriate ADH (SIADH). SIADH represents the sustained, non-physiologic release of ADH and most often occurs as