Pseudohyponatremia is found in all of the following EXCEPT:
Severe hyperlipemia
Extreme hyperproteinemia
Aldosterone excess
Hypothyroidism
Hyponatremia is defined as a plasma level less than 135 meq/L. Most often it reflects excess water, rather than less of Na+, in the plasma. Hence, plasma becomes hypo-osmolar in most instances. Hyponatremia with a normal plasma osmolality is the so-called "pseudohyponatremia". It occurs when plasma lipids or proteins are greatly elevated (options A & B). The proteins or lipids do not increase plasma osmolality significantly. However, they occupy a significant volume of the plasma; and hence the measured in the entire plasma is low. Hyponatremia with normal body Na+ content is seen in hypothyroidism (option D), coisol deficiency, and SIADH. Hyponatremia with increased total body Na+ is seen in edematous states, such as congestive hea failure, cirrhosis of liver, and nephrotic syndrome. Hyponatremia with increased plasma osmolality is seen in hyperglycemia associated with uncontrolled DM. In such a condition, the high plasma glucose causes water to move by osmosis, from cells into plasma. The excess water in ECF leads to hyponatremia.
Endocrine System