Skip to main content

What is kidney dialysis?

Kidney dialysis involves removing waste substances and fluid from the blood that normally are eliminated by the kidneys.

Why it’s done

Kidney dialysis is a procedure performed on those who are suffering from acute or chronic renal failure. Kidney dialysis is also used to prevent renal failure in individuals who have been exposed to or have ingested toxic substances. 


There are two types of kidney dialysis treatments:

Peritoneal dialysis

Peritoneal kidney dialysis is performed by placing a soft, hollow tube into the lower abdomen near the navel. After the tube is inserted, a special solution called dialysate is infused into the peritoneal cavity, the space in the abdomen that contains the organs. The dialysate is left in the abdomen for a designated period of time determined by the physician. Fluids from the dialysate absorb the waste products and toxins through the peritoneum. The fluids are drained, measured and then discarded.

There are two types of peritoneal kidney dialysis that are usually done at home by the patient, family member or caretaker.

  • Continuous Ambulatory Peritoneal Dialysis (CAPD). CAPD requires no machine. Exchanges or "passes" can be done three to five times a day during waking hours.
  • Continuous Cyclic Peritoneal Dialysis (CCPD). CCPD requires a special kidney dialysis machine for home use. This dialysis treatment is done automatically and usually while sleeping.


Hemodialysis is performed in a kidney dialysis center or hospital by trained healthcare professionals. For hemodialysis treatments, a special type of fistula is placed surgically in the arm, and the dialysis patient is then connected to a large hemodialysis machine. The machine drains the blood and bathes it in a special dialysate solution to remove wastes and fluid. The cleaned blood is then returned it to the bloodstream. Hemodialysis is performed several times a week and lasts for four to five hours. Home hemodialysis and nocturnal hemodialysis (done at night) are also options.

Go to top