Peritoneal dialysis (PD) filters and cleans your blood by using your body's peritoneal membrane and dialysate fluid exchanges. You can make your exchanges manually during the day or at night using a peritoneal dialysis machine (also known as a cycler). There are two types of peritoneal dialysis machines: continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). CAPD is done while you sleep and requires the use of several containers to hold the different fluids needed during the procedure. APD is done with a single container that holds all the fluid used during the treatment. Your peritoneal membrane acts like a filter, allowing water and minerals to pass through it but preventing large molecules from doing so. Over time this process removes the waste products from your bloodstream that would otherwise be removed by your kidneys. To accomplish this, you need to connect various tubes and pumps to your body to remove and replace the fluid that passes through your peritoneum. These components include a tube that goes into your abdomen via a catheter, a dialysate solution reservoir, a pump for pushing out spent dialysate, and tubing for returning the fluid to your body. There are several types of peritoneal dialysis machines used in clinical settings. They all work on similar principles but each one has its own advantages and disadvantages.