If the performance of the kidneys, known as “clearance” to specialists, decreases by more than 10 to 15%, complications with dangerous consequences can be expected. Doctors call this stage of blood poisoning uremia. Untreated over a longer period, it leads to death. In treating advanced renal failure, doctors first work to prevent life-threatening complications from uremia while the long-term goal remains the full or nearly complete restoration of a patient’s health, allowing a normal, everyday social and work life. Severely damaged kidneys can only be treated by replacing the organ’s vital functions with an appropriate treatment - renal replacement therapy.