Renal failure and uremia are not the same, where renal failure includes acute and chronic renal failure. Chronic renal failure is a group of syndromes characterized by progressive chronic kidney damage from various causes, clinically characterized by retention of metabolites or toxicants, disturbances in water and electrolyte acid-base balance, and abnormalities in certain endocrine functions. It is a common regression of continued progression of primary or secondary renal lesions and is progressive and irreversible. The end stage of renal failure, i.e., uremia, can be treated medically or otherwise conservatively without the need for renal replacement therapy until renal failure progresses to uremia. When it reaches the uremic stage, patients must undergo renal replacement therapy, which can be hemodialysis, peritoneal dialysis or kidney transplantation.