Peritoneal dialysis uses the natural lining of your abdomen to filter waste from your blood internally, while haemodialysis uses an external machine to clean your blood outside the body. Peritoneal dialysis is typically a daily, home-based treatment, whereas haemodialysis usually requires visiting a hospital or clinic three times per week for several hours at a time.
What We’ll Discuss in This Article
- The fundamental mechanical differences between internal and external blood filtration
- Where each treatment typically takes place and the impact on your daily lifestyle
- The preparation required, including surgical access sites like catheters and fistulas
- Common side effects and risks associated with each specific method
- A direct comparison of treatment schedules, frequency, and time commitments
- How clinical teams help you decide which option aligns best with your medical needs
How peritoneal dialysis works within the body
Peritoneal dialysis is a needle-free treatment that uses the peritoneum, which is a thin membrane covering your abdominal organs, as a natural filter. A small tube called a catheter is surgically inserted into your abdomen. During treatment, a sterile cleaning fluid called dialysate is pumped into the abdominal cavity. This fluid draws out waste and extra water from the blood vessels in the peritoneum before being drained away.
This process, often called an exchange, is typically repeated several times a day or performed overnight using an automated machine. Because the filtration happens daily, it can be gentler on the body than hospital-based methods. It offers patients significant independence, as it can be performed at home or even while travelling. However, it requires a permanent catheter and carries a risk of peritonitis, which is an infection of the abdominal lining.
The process of haemodialysis using an external machine
Haemodialysis involves diverting blood from your body into an external machine, often called an ‘artificial kidney’, where it is filtered through a synthetic membrane before being returned to you. To allow for high-speed blood flow, a surgical procedure is usually required to create an arteriovenous fistula. This is a reinforced connection between an artery and a vein, typically located in the arm.
Most people receiving this treatment attend a hospital or a specialist dialysis unit for four-hour sessions, three times a week. During these sessions, the machine monitors blood pressure and the rate of fluid removal. While this method means you have four treatment-free days per week, it involves needles for every session and can lead to post-dialysis fatigue. Some patients may have the option of home haemodialysis, which allows for more frequent, shorter sessions.
Comparing the core differences in treatment
To help understand the distinct paths of these treatments, the following table compares the essential factors:
| Feature | Haemodialysis | Peritoneal Dialysis |
| Location | Usually hospital or clinic | At home |
| Frequency | 3 times per week (usually) | Daily (day or night) |
| Process | External machine filter | Internal abdominal lining |
| Access | AV fistula (usually in arm) | Catheter (in abdomen) |
| Needles | Required for every session | No needles required |
| Training | Minimal for hospital-based | 1 to 2 weeks for home care |
Causes and requirements for dialysis
Dialysis is required when the kidneys can no longer perform their essential role of filtering the blood, a stage known as end-stage renal disease. This occurs when kidney function drops to approximately 10 to 15 per cent of its normal capacity. At this stage, waste products like urea and excess minerals like potassium build up to dangerous levels, which can be life-threatening if left untreated.
The most common causes for needing dialysis include long-term conditions that damage the kidney filters over time. According to the NHS, diabetes and high blood pressure are the leading factors in kidney failure in the UK. Other causes include glomerulonephritis, which is inflammation of the kidneys, or inherited conditions like polycystic kidney disease. The choice of dialysis depends on a patient’s medical history and remaining kidney function.
Triggers for starting dialysis treatment
The decision to start dialysis is based on a combination of laboratory results and physical symptoms. Clinicians monitor the estimated glomerular filtration rate (eGFR) to track kidney health. When the eGFR falls consistently below 10 or 15, discussions about starting treatment usually begin. However, the presence of specific ‘uraemic symptoms’ often acts as the immediate trigger for starting therapy.
These symptoms include persistent nausea, extreme fatigue, or a metallic taste in the mouth. Fluid overload is another critical trigger, manifested by shortness of breath or significant swelling in the ankles and legs. If these symptoms become unmanageable with medication and diet alone, dialysis is initiated to take over the work the kidneys can no longer do.
Differentiation: Selecting the right method for you
Choosing between the two methods involves balancing medical suitability with lifestyle needs. Peritoneal dialysis is often recommended for those who value flexibility, such as people who work, study, or have an active social life. It is also frequently the first choice for very young children or those who still have some residual kidney function, as it may help preserve that function longer than haemodialysis.
In contrast, haemodialysis may be the better choice for individuals who prefer not to manage their own medical care or who live in housing that cannot accommodate the storage of dialysis supplies. It is often necessary for patients with significant abdominal scarring or those who have had multiple abdominal surgeries, which can make the peritoneum less effective as a filter.
My Final Conclusion
Both peritoneal dialysis and haemodialysis are effective life-sustaining treatments for kidney failure, but they offer very different experiences. Peritoneal dialysis provides daily, at-home flexibility without needles, while haemodialysis offers professional supervision in a clinical setting with several days off per week. Your clinical team will help you weigh these options based on your health status and personal circumstances.
If you experience severe, sudden, or worsening symptoms, such as extreme breathlessness or confusion, call 999 immediately.
Is one type of dialysis better than the other?
Both types are equally effective at filtering the blood; the choice depends on your specific medical needs and lifestyle.
Can I switch from one type of dialysis to another?
Yes, many patients start with one method and switch later due to medical reasons or changes in personal preference.
Is peritoneal dialysis painful?
The process itself is not painful, though some people feel a sensation of fullness when the fluid is in the abdomen.
How long does a haemodialysis session last?
A typical hospital-based session lasts about four hours, three times a week.
Do I need a special diet for dialysis?
Yes, both types require dietary adjustments, though the restrictions for potassium and fluid are often stricter for haemodialysis patients.
Can I still work while on dialysis?
Many people continue to work, especially those on peritoneal dialysis, which can be done around work hours.
Is it possible to travel while on dialysis?
Yes, but it requires careful planning with your dialysis unit to ensure equipment is available at your destination.
Authority Snapshot
This article was written by Dr. Rebecca Fernandez, a UK-trained physician with experience in internal medicine and intensive care. This guide covers the mechanical processes, lifestyle impacts, and clinical requirements for both haemodialysis and peritoneal dialysis. The information is designed to support patient education and align with current UK clinical standards for renal replacement therapy.
