Certified Nephrology Nurse Certification (CNN) Practice Exam 2026 – Comprehensive All-in-One Study Guide for Exam Success!

Osteodystrophy is a condition that arises in patients with chronic kidney disease due to the disruption of the hormonal and metabolic processes that regulate calcium and phosphate metabolism. In the context of kidney disease, the kidneys lose their ability to excrete phosphate efficiently, leading to elevated levels of phosphate in the blood (hyperphosphatemia). This, in turn, causes a decrease in serum calcium levels (hypocalcemia), which stimulates the parathyroid glands to secrete more parathyroid hormone (PTH).

Increased PTH levels contribute to bone disease, as they promote the mobilization of calcium from the bones into the bloodstream in an attempt to correct low serum calcium levels. Moreover, the kidneys also play an essential role in converting vitamin D into its active form, calcitriol, which is crucial for calcium absorption in the gut. Impaired kidney function leads to decreased levels of active vitamin D, exacerbating the calcium deficiency and further disrupting the delicate balance of calcium and phosphate.

Overall, the pathophysiological relationship between chronic kidney disease and osteodystrophy is characterized by these imbalances, resulting in symptoms like bone pain, increased fracture risk, and deformities, which collectively define renal osteodystrophy. This highlights the