Final answer:
The nurse should monitor for signs and symptoms of an Antidiuretic hormone (ADH) imbalance in a client with impaired function of the posterior pituitary gland, which is involved in water balance by influencing kidney function.
Step-by-step explanation:
A client with impaired function of the posterior pituitary gland should be monitored for signs and symptoms of an imbalance in the Antidiuretic hormone (ADH). The anterior pituitary gland produces a variety of hormones like growth hormone (GH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH), but not ADH. ADH is produced by the hypothalamus and then stored and released by the posterior pituitary gland. It is crucial for water balance in the body, influencing the kidneys to reabsorb water and concentrate urine. Therefore, an impaired posterior pituitary function can lead to conditions such as diabetes insipidus, characterized by excessive thirst and large volumes of urine.