Final answer:
A nurse should expect to find hypercalcemia in a client diagnosed with hyperparathyroidism due to the overproduction of parathyroid hormone leading to high blood calcium levels and associated symptoms.
Step-by-step explanation:
In cases of hyperparathyroidism, a nurse should expect to find hypercalcemia, which is characterized by abnormally high levels of calcium in the blood. This condition occurs because the parathyroid glands produce excess parathyroid hormone (PTH), which causes the bones to release more calcium into the bloodstream and reduces the amount of calcium excreted by the kidneys. As a result patients may present with symptoms such as lethargy sluggish reflexes, and constipation due to the depressed nervous system function associated with high blood calcium levels.
Additionally, hyperparathyroidism often leads to low serum phosphate or hypophosphatemia, due to increased renal phosphate excretion stimulated by the excess PTH. This makes option A, Hypercalcemia the correct choice for a client diagnosed with hyperparathyroidism.