In medicine, dialysis (from Greek διάλυσις, Dialysis, "dissolution"; from διά, dia, "through", and λύσις, lysis, "loosening or splitting") 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.Dialysis is used as a temporary measure in either acute kidney injury or in those awaiting kidney transplant and as a permanent measure in those for whom a transplant is not indicated or not possible. In Australia, Canada, the United Kingdom, and the United States, dialysis is paid for by the government for those who are eligible. The first successful dialysis was performed in 1943. In research laboratories, dialysis technique can also be used to separate molecules based on their size. Additionally, it can be used to balance buffer between a sample and the solution "dialysis bath" or "dialysate"[3] that the sample is in. For dialysis in a laboratory, a tubular semipermeable membrane made of cellulose acetate or nitrocellulose is used.[4] Pore size is varied according to the size separation required with larger pore sizes allowing larger molecules to pass through the membrane. Solvents, ions and buffer can diffuse easily across the semipermeable membrane, but larger molecules are unable to pass through the pores. This can be used to purify proteins of interest from a complex mixture by removing smaller proteins and molecules.Dialysis is needed when a child's kidneys stop working properly. Dialysis is one form of renal replacement therapy (RRT) and transplantation is the other. Dialysis will make your child feel better but it does not make them feel normal or return the blood test results to normal, as we hope will happen with transplantation. Dialysis is used until transplantation is possible.Dialysis does the job that is normally carried out by the kidneys. That is, it takes away the substances that the body does not need that would otherwise build up in the blood and make someone ill. Dialysis also removes salt and water from the body if the kidneys have reduced the amount of urine they are making.