Certified Nephrology Nurse Certification (CNN) Practice Exam 2025 - Free Nephrology Nursing Practice Questions and Study Guide

The retention of waste products in chronic kidney disease is primarily due to a decrease in renal function. In chronic kidney disease (CKD), the kidneys gradually lose their ability to filter waste products and excess fluids from the bloodstream. This decreased glomerular filtration rate impairs the kidneys' capacity to excrete urea, creatinine, and other metabolic wastes, leading to their accumulation in the body.

As renal function diminishes, the kidneys cannot maintain homeostasis effectively, which can result in worsening metabolic derangements and other complications associated with CKD. While conditions like hypertension, glomerulonephritis, and diabetes are significant risk factors for the progression of CKD, they are more about the underlying causes or complications of kidney impairment rather than the direct mechanism of waste product retention itself. Therefore, the correct choice directly relates to the core pathology of CKD and its impact on renal function.