dialysis is the process of removing excess water, solutes, and toxins from the blood in people whose kidneys can no longer perform these functions naturally. This is referred to as renal replacement therapy.

Dialysis may need to be initiated when there is a sudden rapid loss of kidney function, known as acute kidney injury (previously called acute renal failure), or when a gradual decline in kidney function -chronic kidney disease reaches stage 5. Stage 5 chronic renal failure is reached when the glomerular filtration rate is 10-15% of normal, creatinine clearance is less than 10mL per minute and uremia is present.