What is the main function of the kidneys that is compromised in kidney failure?

The main function of the kidneys that is compromised in kidney failure is the filtration of waste products from the blood. In healthy kidneys, nephrons work diligently to filter out toxins, excess salts, and metabolic waste while also retaining the substances that the body needs. When kidney function declines due to failure, this filtration process becomes impaired, leading to the accumulation of waste products in the bloodstream, which can result in toxic effects on the body.

In the case of advanced kidney failure, individuals may experience increased levels of urea and creatinine, both of which are byproducts of metabolic processes that normally would be eliminated by the kidneys. This poor filtration function is critical because it not only affects waste management but also disrupts electrolyte balance and can lead to fluid overload, potentially resulting in serious health complications.

While the kidneys also play roles in regulating blood pressure, producing red blood cells through erythropoietin signaling, and contributing to metabolic processes such as maintaining blood sugar levels, these functions are secondary in the context of acute waste filtration failure. The immediate impact of kidney failure is seen most prominently in the inability to effectively filter waste from the blood.