Editing Medical-Surgical Nursing (section)

=== Pituitary and Water Balance Disorders ===

Syndrome of inappropriate antidiuretic hormone causes water retention with dilutional hyponatremia, concentrated urine with high specific gravity, low serum osmolality, weight gain without edema, and neurologic changes. Management is fluid restriction, sodium monitoring, and sometimes hypertonic saline for severe symptomatic hyponatremia, corrected slowly.

Diabetes insipidus is the mirror image: deficient antidiuretic hormone causes massive output of very dilute urine with low specific gravity, intense thirst, hypernatremia, and risk of hypovolemic shock. Management is fluid replacement and desmopressin.