Peritoneal dialysis (PD) is one of the most common renal replacement therapies that end- stage renal disease patients undergo. Adequacy of PD in Mexico showed no survival benefit of an increased dose of small molecule clearance by PD, but fluid overload was associated with mortality in PD patients. Recent studies lead to paradism shift from solute clearance to volume status in PD patients. A dilution method using deuterium oxide or bromide is the gold standard for predicting volume status. However, this method requires expensive equipment and a relatively long evaluation time. Bioimpedance analysis, lung comets, or biomarkers are used to evaluate volume stauts in PD patients. Although bioimpedance analysis is a popular method for estimating volume status in PD patients, there were inconsistent results regarding the effect of bioimpedance guided volume control in PD. Several strategies are used to achieve euvolemia; retriction of salt and water intake, diuretics, change in PD prescription, and transfer to hemodialysis. Ultrafiltration failure (UFF) is a significant cause of PD shortage and defined as < 400 ml of ultrafiltration during a 4 hr dwell using 4.25% glucose dialysate. Recent International Society for Peritoneal Dialysis guideline states three issues for UFF; (1) to provide a new clinicopathological classification of membrane dysfunction, (2) to provide guidance on which membrane tests can be used to establish evidence of membrane dysfunction and (3) to assist clinicians with the interpretation of these tests and their implications for clinical management. In addition, some terminologies have been changed to better understand mechanisms of membrane dysfunction.