What is Dialysis?
[[File:Hemodialysismachine.jpg|thumb|A dialysis machine]] '''Dialysis''' is where a machine is used to replace a [[kidney]] after [[kidney failure]]. The word ''dialysis'' comes from the Greek word ''dialusis'', ''dia'' meaning through, and ''lusis'' meaning loosening. Dialysis can be used for people who have become sick and have lost the use of their kidneys for a short time, or for people who no longer have working kidneys. The purpose of the kidney is to keep a balance of water and minerals in the body. These minerals include [[sodium]], [[potassium]], [[chloride]], [[calcium]], [[phosphorous]], [[magnesium]] and [[sulfate]]. The kidneys also take out [[hydrogen]] [[ion]]s from the blood. Dialysis is able to remove these wastes from the body and help keep the minerals in balance.<ref>http://www.kidneyatlas.org/book5/adk5-01.ccc.QXD.pdf {{Webarchive|url=https://web.archive.org/web/20110726220946/http://www.kidneyatlas.org/book5/adk5-01.ccc.QXD.pdf |date=2011-07-26 }} Atlas of Diseases of the Kidney, Volume 5, Principles of Dialysis: Diffusion, Convection, and Dialysis Machines</ref> However the kidneys are also part of the [[endocrine system]] and make [[erythropoietin]] and [[calcitriol]]. Dialysis machines are not able to replace this part of the kidney's function. == How dialysis works == Dialysis machines work by using [[diffusion]] and [[ultrafiltration]]. A very fine material, called a [[membrane]], allows blood and fluid to flow through it. In the machine, the blood flows in one direction, and on the other side of the membrane, a special fluid, dialysate flows in the opposite direction, this process is known as [[osmosis]]. Dialysate is a fluid that has different chemicals in it, such as potassium and calcium. A doctor would decide what mixture of chemicals would be needed for each patient. The dialysate has [[bicarbonate]] in it to lower the higher acid levels that these patients often have. The blood and dialysate mix together. The waste products are removed from the blood and caught up in the fine