In more advanced stages there are nausea, vomiting, difficulty breathing, aggravated high blood pressure, and very little urine production. Dialysis replaces about 10 to 15 percent of the kidney's filtering capacity. This has a significant effect on decreasing the symptoms of uremia and dramatically improving the quality of life of a patient. In this type of dialysis, an artificial unit called a dialyzer mimics the action of the nephron. To undergo hemodialysis, a person must first have a minor surgical procedure to create an access for the needles and tubing needed to connect the blood circulation to the dialysis machine.
Most people undergo three dialysis sessions each week, for about four hours each time.
A person is connected to the dialysis machine via the shunt. The dialysis machine pumps the blood through the dialyzer, which filters off the waste products, excess fluid, and excess body chemicals. The newly cleaned blood flows out of the dialyzer and is returned via a different set of tubes. During dialysis, a person also recieves the hormones the kidneys are unable to produce. Most hemodialysis is performed at a dialysis center, specialized centers staffed by nurses and dialysis technicians with thorough training in the process.