Last updated: 2 November 2026
There are two main types of dialysis: hemodialysis, which filters blood outside the body using a machine called a dialyzer, and peritoneal dialysis, which filters blood inside the body using the lining of the abdomen (the peritoneum) as a natural filter.
Hemodialysis is usually done at dialysis unit three times a week for about four hours per session, while peritoneal dialysis is typically self-managed at home, either through several manual exchanges a day or an automated overnight cycle. Both remove waste, excess fluid, and toxins from the blood when the kidneys can no longer do this on their own. Choice of modality of dialysis depends on a person’s medical and surgical history, lifestyle, home support which a nephrologist evaluates case by case.
Key Takeaways
- There are 2 main types of dialysis: hemodialysis, which cleans the blood through a machine, and peritoneal dialysis, which uses the lining of the abdomen as a filter.
- Hemodialysis is usually done at a dialysis unit about three times a week; peritoneal dialysis is done every day at home.
- Neither type is better for everyone. The choice depends on your health, abdominal surgery history, veins, home set-up and lifestyle.
- Dialysis does not cure kidney failure, but it removes waste and extra fluid so you can feel better and stay active.
- You can switch from one type to the other, and a kidney transplant remains an option for many patients.
Introduction
A kidney failure diagnosis brings a flood of new terms, and “dialysis” is usually the first one that needs explaining. If you or a loved one has just been told that dialysis may be needed, you’ve probably already heard the two options mentioned: hemodialysis and peritoneal dialysis. Understanding what separates them, including how they work, where they happen, and how they fit into daily life, makes an overwhelming decision feel much more manageable.
This guide breaks down both types of dialysis in plain language, compares them side by side, and covers what happens before, during, and after treatments.
What is Dialysis?
Dialysis is a medical treatment that takes over the job of filtering the blood when the kidneys can no longer do it effectively. Healthy kidneys remove waste products, balance electrolytes, and eliminate extra fluid around the clock. Dialysis may be required in advanced kidney failure when the kidneys can no longer adequately control waste, fluid or electrolyte levels. The decision is based on symptoms, laboratory findings and the patient’s overall condition.
Dialysis doesn’t cure kidney disease and it doesn’t fully replace the kidneys’ many functions, but it does the essential job well enough to keep patients alive and functioning. Kidney failure affects a substantial number of people worldwide. In the United States alone, more than 800,000 people are living with kidney failure, and the majority of them rely on one of the two main types of dialysis to survive.
Why Dialysis is Necessary
When kidney function declines, the body’s internal balance breaks down in ways that become life-threatening if untreated. Dialysis steps in to:
- Remove waste products and toxins (such as urea and creatinine) that build up in the blood
- Eliminate excess fluid that the kidneys can no longer excrete, preventing dangerous fluid overload
- Correct electrolyte imbalances, particularly dangerously high potassium levels
- Help regulate blood pressure, which kidneys normally influence through fluid and hormone control
Without dialysis or a transplant, untreated kidney failure leads to complications such as uremia, severe fluid overload affecting the heart and lungs, and life-threatening electrolyte disturbances.
Signs That Dialysis May Be Needed
Dialysis usually becomes necessary in stage 5 chronic kidney disease, also called kidney failure, when the eGFR (a blood test measure of kidney function) falls below 15. Your nephrologist looks at blood test trends and symptoms together, not one number alone. Common signs include:
- Swelling of the feet, ankles, face or hands that does not settle
- Breathlessness from fluid building up in the lungs
- Nausea, vomiting or loss of appetite, often with weight loss
- Persistent itching, muscle cramps or restless legs
- Tiredness, poor concentration or confusion from waste building up in the blood
- Passing very little urine
- Dangerously high potassium or acid levels on blood tests that do not respond to medicines
Severe breathlessness, confusion or chest pain in someone with kidney disease is an emergency. Call 108 for an ambulance.
The 2 Main Types of Dialysis: A Quick Overview
| Feature | Hemodialysis | Peritoneal Dialysis |
| How it filters blood | External machine (dialyzer) filters blood outside the body | Body’s own peritoneal lining filters blood inside the abdomen |
| Where it’s usually done | Dialysis center or hospital (home hemodialysis also possible) | At home, often self-administered |
| Access point | Arteriovenous (AV) fistula, graft, or catheter, usually in the arm | Soft catheter placed in the abdomen |
| Frequency | Typically 3 sessions per week, ~4 hours each | Daily either several manual exchanges or one overnight automated cycle |
| Needles required | Yes, at each session | No needles; uses the abdominal catheter |
| Level of independence | Lower: relies on clinic staff and fixed schedule | Higher: patient manages their own schedule |
| Diet/fluid restriction | Generally stricter, especially between sessions | Somewhat more flexible due to daily fluid removal |
| Common risks | Low blood pressure, muscle cramps, vascular access infection | Peritonitis (abdominal infection), catheter-site infection |
| Best suited for | Patients who prefer clinical supervision or lack a suitable home setup | May be considered for suitable patients who experience difficulty tolerating conventional hemodialysis, including recurrent low blood pressure during sessions. |
Hemodialysis: How it Works
The Process, Step by Step
- Access creation. Before starting hemodialysis, a surgeon creates a vascular access point, usually an AV fistula (a connection between an artery and vein) or an AV graft in the arm. In urgent situations, a temporary central venous catheter may be used instead.
- Blood withdrawal. During each session, two needles are inserted into the access site. Blood flows out through one needle toward the dialysis machine.
- Filtering. Inside the dialyzer, often called an “artificial kidney”, blood passes along one side of a semi-permeable membrane while a cleansing fluid called dialysate flows along the other side. Waste products and excess fluid move across the membrane into the dialysate.
- Return. The filtered blood flows back into the body through the second needle.
Types of Dialysis Access: Fistula, Graft and Catheter
Dialysis access is the entry point that lets blood or fluid move in and out for each session. Each of the 2 types of dialysis needs its own access, and the US National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) describes the AV fistula as the best option for hemodialysis because it gives the highest blood flow, is less likely to become infected or clot, and lasts longer.
| Access | Used for | What to know |
|---|---|---|
| AV fistula | Hemodialysis | An artery joined to a vein in the arm. Healing can take several months, so it is best made well before dialysis starts |
| AV graft | Hemodialysis | A soft tube joining an artery and a vein when the veins are too small for a fistula. Usable soon after surgery, but more prone to infection and clots |
| Hemodialysis catheter | Hemodialysis | A tube in a large vein in the neck, chest or groin. Used as a temporary access, often for an urgent start, while a fistula matures |
| PD catheter | Peritoneal dialysis | A soft tube placed through the wall of the abdomen. Ideally placed at least 3 weeks before the first exchange so the site can heal |
Frequency and Setting
Patients require dialysis two or three times a week, with each session lasting about three to five hours. Some patients qualify for home hemodialysis, which can be done more frequently in shorter sessions, offering more flexibility once training is complete.
Who Hemodialysis Suits Best
Hemodialysis tends to work well for patients who:
- Prefer regular contact with medical staff and close monitoring
- Don’t have a home environment suited to self-managed treatment
- Have certain abdominal conditions (like extensive prior surgery or hernias) that rule out peritoneal dialysis
- Want a treatment schedule that doesn’t require daily involvement.
Peritoneal Dialysis: How It Works
Peritoneal dialysis (PD) uses the peritoneum, the natural membrane lining the abdominal cavity, as the filter, rather than an external machine.
The Process, Step by Step
- Catheter placement. A soft, flexible catheter is surgically placed into the abdomen, usually several weeks before treatment begins to allow healing.
- Fill. A sterile dialysate solution flows through the catheter into the abdominal cavity.
- Dwell. The solution stays in the abdomen for a set period during which waste products and excess fluid pass from the blood vessels lining the peritoneum into the dialysate.
- Drain. The used solution, now carrying the waste, is drained out and replaced with fresh solution.
Two Ways to Perform Peritoneal Dialysis
- Continuous Ambulatory Peritoneal Dialysis (CAPD): Manual exchanges done by the patient, usually about 4 times a day as prescribed by the nephrologist, each taking around 30 to 40 minutes. “Ambulatory” means you can walk about and carry on with normal activities while the fluid stays in the abdomen between exchanges.
- Automated Peritoneal Dialysis (APD): A machine called a cycler performs multiple exchanges automatically overnight while the patient sleeps, often freeing up the daytime hours entirely.
Who Peritoneal Dialysis Suits Best
Peritoneal dialysis tends to work well for patients who:
- Want to preserve independence and manage treatment around work, school, or travel
- Prefer to avoid repeated needle insertions
- Have some residual kidney function, which PD tends to preserve slightly longer than hemodialysis in some patients
- Have a clean, suitable space at home and the ability (or a caregiver’s ability) to follow sterile technique
- Live far from a dialysis unit, as many families in smaller towns and villages do, and want to avoid travelling to a centre several times a week
Which Types of Dialysis Can Be Done at Home?
Three types of dialysis can be done at home: CAPD, APD and home hemodialysis. CAPD needs no machine, only bags of dialysis fluid. APD uses a bedside machine called a cycler that runs overnight. Home hemodialysis uses a smaller hemodialysis machine and needs a trained care partner, space for the machine and a reliable water and power supply. In-centre hemodialysis uses a larger machine with a dialyzer, the filter often called an artificial kidney.
Are There Other Types of Dialysis? CRRT and Kidney Transplant
People often ask about a third type of dialysis. Apart from hemodialysis and peritoneal dialysis, doctors use a few other kidney replacement options in specific situations:
| Option | What it is | Who it is for |
|---|---|---|
| CRRT (continuous renal replacement therapy) | A slower form of blood filtering that runs around the clock in the ICU | Critically ill patients whose blood pressure cannot cope with a standard hemodialysis session |
| Home hemodialysis | Hemodialysis done at home after training, often in shorter, more frequent sessions | Patients with a trained partner and space for the machine |
| Kidney transplant | A healthy kidney from a living or deceased donor replaces the failed kidneys | Patients fit for surgery; it removes the need for dialysis while the new kidney works |
| Conservative care | Treatment without dialysis that focuses on symptoms and comfort | Some older or very frail patients, after a shared decision with the care team |
According to the US National Institute of Diabetes and Digestive and Kidney Diseases, a transplant filters waste better than dialysis, though it is still not a cure and needs lifelong anti-rejection medicines. Many patients start dialysis while they are evaluated or wait for a donor kidney.
How Do Doctors Decide Which Type Is Right for You?
There’s no single “better” option. The right type of dialysis depends on individual medical and lifestyle factors. A nephrologist typically weighs:
| Decision Factor | Favors Hemodialysis | Favors Peritoneal Dialysis |
| Home environment and support | Limited space or hygiene concerns | Clean, suitable home setup available |
| Desire for independence | Prefers clinical supervision | Wants to manage treatment personally |
| Abdominal surgical history | Extensive prior abdominal surgery | No major abdominal surgery |
| Residual kidney function | Lower priority | May help preserve residual function longer |
| Vascular access suitability | Good veins for AV fistula/graft | Vascular access is difficult to establish |
| Lifestyle and travel needs | Fixed local schedule works fine | Frequent travel or irregular routine |
This decision is made collaboratively between the patient and their nephrology team.
Questions to Ask Your Nephrologist
Before you choose between the two options, these questions help you compare them for your own life:
- Which type suits my health, and why?
- What access will I need, and how long before starting should it be created?
- How much training is needed, and who can be my care partner at home?
- Can I keep working, travelling or caring for my family?
- How will dialysis affect my diabetes, blood pressure or heart condition?
- Am I suitable for a kidney transplant, and when should I start the evaluation?
After Dialysis Care: What Comes Next Matters Just as Much
Dialysis doesn’t end the moment the session or exchange is complete. Proper aftercare directly affects how well patients feel and how few complications they experience.
After Hemodialysis Care
- Dietary adjustments. Fluid intake stays within prescribed limits. A kidney-friendly diet typically lower in potassium, phosphorus, and sodium supports recovery and reduces strain before the next session.
- Access site monitoring. Watch the fistula, graft, or catheter site for swelling, redness, warmth, or discharge and report these to the care team promptly.
- Symptom tracking. Dizziness, unusual fatigue, or cramping after a session should be discussed with the dialysis team rather than dismissed as routine.
Protecting Your Fistula or Graft Arm at Home
A fistula or graft arm needs everyday protection at home, because hemodialysis depends on that one access working at every session. These rules come from the US National Library of Medicine’s MedlinePlus guide to caring for a vascular access. Family members who help with care can follow them too:
- Check the flow every day. Blood moving through a working fistula or graft makes a mild vibration, called a thrill, that you can feel over the access. Your dialysis team will show you how to check it.
- Keep the access arm for dialysis only. Do not let anyone take your blood pressure, start an IV line or draw blood from that arm. Say so at every clinic and laboratory you visit.
- Wear nothing tight over the access: no watch, bangles or other jewellery, and no tight sleeves.
- Do not sleep on the access arm.
- Do not carry heavy bags or loads with the access arm. MedlinePlus gives 4.5 kg as the limit. Ask your dialysis unit what limit applies to you.
- Wash the skin around the access with soap and warm water every day, as the NIDDK advises.
Contact your dialysis unit right away if the thrill slows down or you cannot feel it, if you see redness, swelling, soreness, warmth or pus, if you have a fever or chills, or if your hand turns cold, numb or weak.
If the access bleeds, apply steady pressure with clean gauze or a clean towel, as the US National Kidney Foundation advises, and tell your dialysis unit right away. If the bleeding is heavy or spurting, or does not stop after pressure, call 108.
After Peritoneal Dialysis Care
- Catheter site hygiene. Daily cleaning of the exit site, following the technique taught during training, significantly lowers infection risk.
- Fluid and diet management. Following prescribed dietary guidance helps manage electrolyte levels and prevents fluid overload
- Watch for peritonitis signs. Cloudy drained fluid, abdominal pain, or fever needs same-day medical attention, it could be peritonitis which requires treatment with antibiotics.
- Routine follow-ups. Regular review with the nephrology team confirm the treatment is clearing waste effectively (measured through periodic lab tests).
Risks and Benefits at a Glance
| Hemodialysis | Peritoneal Dialysis | |
| Key benefits | Effective toxin removal; close professional monitoring; no daily self-management required | Greater independence; can be done at home or while traveling; no needles |
| Key risks | Low blood pressure, variation in heart rate, muscle cramps, vascular access infection or clotting | Peritonitis, catheter-site infection, bloating or discomfort |
| Time commitment | Fixed clinic schedule, about 12 to 15 hours a week | Daily, but flexible around personal routine |
Living Well with Dialysis
Whichever type of dialysis you’re on, a few habits consistently support better outcomes and quality of life:
- Stay physically active. Light to moderate exercise, cleared by your care team, improves circulation, supports muscle strength, and helps combat dialysis-related fatigue.
- Stick to your kidney-friendly diet. Managing potassium, phosphorus, sodium, and fluid intake reduces the burden on each dialysis session and helps prevent complications between treatments.
- Prioritize emotional wellbeing. Chronic illness takes a psychological toll; support groups, counseling, or talking openly with family can make a meaningful difference.
- Keep every follow-up appointment. Routine blood work and reviews identify issues like infections, access issues, inadequate dialysis dosing, before they become emergencies.
- Get vaccinated as recommended. Dialysis patients are more vulnerable to certain infections; staying current on recommended vaccines is an easy, evidence-based protective step.
Hospice and Comfort-Focused Dialysis Care
For patients with advanced illness who choose to prioritize comfort over aggressive treatment, dialysis can still play a role, but with a different goal. Comfort-focused (hospice-aligned) dialysis adjusts the treatment plan to reduce symptom burden rather than maximize toxin clearance, alongside palliative support for pain, breathlessness, and emotional distress. This is always a deeply personal decision made together by the patient, their family, and their care team, and it’s one that should be revisited regularly as circumstances change.
Conclusion
Hemodialysis and peritoneal dialysis are the two primary types of dialysis, and each offers an effective way to manage kidney failure. They work in different ways. The two main types of dialysis are hemodialysis and peritoneal dialysis. Hemodialysis filters blood through a machine, while peritoneal dialysis uses the lining of the abdomen as a natural filter.
If you or a family member is facing this decision, know that both paths lead to the same goal: keeping the body in balance and preserving quality of life. With the right treatment, aftercare, and support system, many dialysis patients continue to work, travel, spend time with family, and live full lives.
For a personalized evaluation, Medway Hospitals’ nephrology team offers dialysis planning, vascular and peritoneal access procedures, and ongoing kidney care across all our branches.
Read Also : Best Nephrologist in Chennai
Need Help Choosing the Right Dialysis Option?
Speak with Medway Hospitals’ nephrology team for an individual kidney and dialysis assessment.
