When kidney failure, or end stage renal disease, develops patients require dialysis. To replace the work of the kidneys by cleaning the blood of waste products. Dialysis is frequently performed by direct cleansing of the blood, known as hemodialysis; a process where blood is removed from the body and passed through a machine called a dialyzer. The clean blood is then pumped back into the blood stream. Hemodialysis is usually done every other day.