When dialysis is needed
Dialysis is generally needed when the kidneys can no longer adequately filter waste, balance fluid, and regulate electrolytes — typically when the eGFR drops to around 10–15 (Stage 5 CKD, also called end-stage renal disease or ESRD) and symptoms of kidney failure appear. Symptoms may include nausea, fatigue, swelling, shortness of breath, and trouble concentrating. The exact timing is individualized: some patients start earlier, some later.
What dialysis does (and does not) do
Dialysis replaces the filtering function of the kidneys, removing waste products and excess fluid. It does not replace the hormonal functions — vitamin D activation, erythropoietin production, blood pressure regulation — which is why patients on dialysis often still need additional medications to manage anemia, bone health, and blood pressure.
The two main types
Hemodialysis (HD)
In hemodialysis, blood is removed from the body through a vascular access (typically an arteriovenous fistula in the arm), pumped through an artificial kidney machine that filters out waste, and returned to the body. Most patients receive hemodialysis at a dialysis center three times per week for about four hours per session. Some patients can do hemodialysis at home, often with shorter, more frequent sessions that are gentler on the body.
Peritoneal Dialysis (PD)
In peritoneal dialysis, the lining of the abdomen (the peritoneum) is used as a natural filter. A sterile fluid is introduced into the abdomen through a permanent catheter and left to dwell, allowing waste to diffuse out of the blood vessels in the abdominal lining. The fluid is then drained and replaced. PD is done at home, either through manual exchanges during the day or automatically overnight using a cycler machine.
Choosing between hemodialysis and peritoneal dialysis
Both therapies can be effective. The choice depends on lifestyle, work and travel patterns, support at home, abdominal anatomy, and personal preference. Many patients value the lifestyle flexibility of home therapies (PD or home HD); others prefer the structure of in-center care.
Vascular access
For hemodialysis, a stable vascular access is essential. The preferred option is an arteriovenous fistula — a surgically created connection between an artery and a vein in the arm. Fistulas typically need three to six months to mature before they can be used, which is why early planning is so important.
Life on dialysis
Many people on dialysis continue to work, travel, and live full lives. Diet generally requires more attention — controlling potassium, phosphate, and sometimes fluid intake. Most dialysis units arrange travel-dialysis at partnering centers for vacations or business trips.
Kidney transplantation as an alternative
For most patients, kidney transplantation provides better long-term outcomes than dialysis — longer life expectancy, better quality of life, and fewer dietary restrictions. Patients who may be candidates should be evaluated by a transplant center as early as possible, ideally before dialysis is even started (preemptive transplantation).