What Is Dialysis?

Dialysis is a life-saving medical treatment used when the kidneys are no longer able to perform their essential functions effectively. The kidneys normally filter waste products, remove excess fluids, and maintain a healthy balance of electrolytes in the body. When kidney function declines significantly—especially in advanced Chronic Kidney Disease (CKD) or kidney failure—dialysis takes over these critical roles.

There are two main types of dialysis: hemodialysis and peritoneal dialysis. Hemodialysis involves using a machine and a special filter to clean the blood outside the body, while peritoneal dialysis uses the lining of the abdomen (peritoneum) to filter blood internally. The choice of dialysis depends on the patient’s condition, lifestyle, and medical needs.

How Does Dialysis Work?

Dialysis works by performing the key functions of healthy kidneys—removing waste, balancing fluids, and maintaining proper chemical levels in the body. In hemodialysis, blood is drawn from the body through a vascular access (such as a fistula or catheter), passed through a dialysis machine where it is filtered, and then returned to the body. This process usually takes place several times a week under medical supervision. In peritoneal dialysis, a special fluid is introduced into the abdominal cavity through a catheter.