Healthy kidneys keep a balance of water and chemicals in your blood all the time. (We call this balance homeostasis.) To do this, they:
- Filter out water and wastes
- Control blood pressure
- Make hormones
Just 50 years ago, if you had chronic kidney disease and your kidneys failed, you would have died. There was no treatment that could save your life. Now there are two: kidney transplant and dialysis.
Dialysis is a treatment that can clean the blood. A filter is used to remove wastes. A membrane (thin layer of tissue) keeps blood separate from a special fluid called dialysate. The membrane has tiny pores in it that let wastes and water out. Protein and other large cells your body needs to keep are too big to fit through the pores.