The job of the kidneys is to remove waste and extra water from the body. The kidneys also balance levels of minerals in the body, called electrolytes. Kidneys are essential for the health of the body. People with severe kidney disease are not able to perform these functions. This may be due to a temporary or a permanent kidney condition. Hemodialysis is a treatment that takes over the essential functions of the kidney until you recover from kidney disease or get a kidney transplant. If you have end-stage renal disease (ESRD) and are not eligible for a transplant, you will need to have hemodialysis for the rest of your life. Peritoneal dialysis is another type of dialysis. But it's not covered in this article.
Hemodialysis requires access to a strong blood flow. There are three ways to do this.
- Dialysis catheter. This is a plastic tube put into a large blood vessel, usually for temporary access. If there is no other option, it may be used permanently.
- AV fistula. Through a minor surgical procedure, an artery in your arm is joined directly to a vein. This creates an arteriovenous fistula, or AV fistula. The pressure of the arterial blood flow slowly expands the size of the attached vein. It may take up to 4 to 6 weeks for the fistula to enlarge enough to be ready for dialysis. The AV fistula is the access of choice. This is because there are typically fewer problems and side effects. It also lasts longer than the other options.
- AV graft. This is an artificial implant. It joins an artery and vein in people with small veins. It can also be used when an AV fistula did not work. It can be used for dialysis a few weeks after the surgery.
A connecting tube carries blood from the access point in the body to the dialysis machine. Then, special filters called dialyzers filter and process the blood. The blood is then returned to the body through a separate tube and needle. This takes 3 to 4 hours. It's usually done 3 times a week. Home dialysis is an option for some people.
Hemodialysis is lifesaving for people with kidney failure. But there are possible side effects. These include infection, low blood pressure, bleeding, electrolyte imbalance, anemia, and heart disease. People on hemodialysis are educated and closely monitored to minimize these risks as much as possible.