Fluid overload in peritoneal dialysis (PD) patients is common and can manifest as generalized edema, pulmonary edema, and hypertension. It contributes to left ventricular hypertrophy and is a major contributor to cardiovascular disease, the leading cause of death in all dialysis patients. It is also associated with hypoalbuminemia, malnutrition, inflammation, and atherosclerosis; and it is a significant cause of technique failure, especially in long-term PD patients.   Often, multiple causes of volume overload coexist in an individual PD patient. For example, there may be some UFF but also excess dietary salt intake or poor glucose control. Optimal management may therefore require multiple therapeutic and preventive strategies.   While peritoneal dialysis provides effective control of many of the diverse consequences of uremia, the therapy itself has unique effects on several metabolic parameters that are important for the health of patients with end-stage renal disease. 10~ 30 percent of patients treated with PD are reported to have low serum potassium levels. There are several potential reasons for this high prevalence of hypokalemia.   Hyponatremia is quite common in PD patients, and one center recently reported a prevalence of 15%. Translocational hyponatremia can occur due to hyperglycemia, with the serum sodium falling about 1.3 mmol/L for each 6 mmol/L rise in blood glucose. In contrast, treatment with PD has the potential to induce hypernatremia.   By having an understanding of the pathophysiology behind the fluid and electrolyte abnormalities that occur in end-stage renal disease, one can direct proper management with medications, diet, and alterations in dialysis to provide patients with the most optimal form of renal replacement therapy available.