The patient, however, manifested no symptoms of acute hyponatremia ... abruptly increased to 300 ml/h. Her serum sodium level was 145 mmol/l with a plasma osmolality of 298 mOsm/kg H 2 O, and ...

Water and sodium retention during severe hypothyroidism create a state of volume depletion, low extracellular fluid osmolality and ... characterized by normal serum levels of thyroid hormones ...