Hemodialysis filters your blood through an external machine, while peritoneal dialysis uses the lining of your abdomen as a natural filter. Both accomplish the same goal: removing waste, excess fluid, and toxins that your kidneys can no longer handle. But they differ significantly in how they work, where they’re performed, how often they’re needed, and how they shape your daily life.
How Each Method Filters Your Blood
In hemodialysis, blood is drawn out of your body and passed through a device called a dialyzer. Inside the dialyzer, hollow tube-like fibers create a large surface area where your blood flows in one direction and a cleaning fluid (called dialysate) flows in the opposite direction. This counterflow maximizes the removal of waste products through diffusion. Excess water is pulled from your blood using pressure, much like squeezing fluid through a filter.
Peritoneal dialysis takes a completely different approach. A cleaning solution is pumped through a catheter into the peritoneal cavity, the open space inside your abdomen. The peritoneum, a highly vascular membrane lining that cavity, acts as the filter. Waste and toxins from your bloodstream naturally diffuse across this membrane into the fluid. Instead of mechanical pressure, peritoneal dialysis relies on the sugar (glucose) concentration in the fluid to draw excess water out of your blood through osmotic pressure. Higher glucose concentrations pull more fluid. After the solution has done its job, it drains out through the same catheter and is replaced with fresh fluid.
Schedule and Time Commitment
In-center hemodialysis typically requires three sessions per week, each lasting about three to five hours. You travel to a dialysis center, sit in a chair while connected to the machine, and return home afterward. Some people do hemodialysis at home, which can allow for more frequent or longer sessions on a more flexible schedule, but the equipment is substantial.
Peritoneal dialysis is a daily treatment. The two main forms are continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis (APD). With CAPD, you manually exchange the fluid in your abdomen several times throughout the day, with each exchange taking about 30 to 40 minutes. With APD, a machine called a cycler performs the exchanges automatically while you sleep, freeing up your daytime hours. Because the treatment happens at home and doesn’t require a large machine or specialized water system, many patients find it easier to maintain a normal routine.
Surgical Access: What Goes Into Your Body
Both types of dialysis require a minor surgical procedure before treatment can begin, ideally weeks or months in advance.
For hemodialysis, you need vascular access that can handle the high blood flow the machine requires. The preferred option is an arteriovenous (AV) fistula, where a surgeon connects an artery directly to a vein, usually in your forearm. This causes the vein to enlarge and strengthen over time, making it durable enough for repeated needle insertions. If your veins are too small for a fistula, a synthetic tube called an AV graft can bridge an artery and vein instead. For patients who need dialysis urgently, a central venous catheter is placed into a large vein in the neck, chest, or groin as a temporary solution.
Peritoneal dialysis requires a soft plastic catheter inserted through the abdominal wall into the peritoneal cavity. It stays in place permanently and is used for every fluid exchange. The surgical placement is simpler than creating a fistula, but the catheter needs time to heal before use.
Infection Risks Differ by Type
Infection is a serious concern with both methods, but the types of infection differ. In peritoneal dialysis, the primary risk is peritonitis, an infection of the peritoneal membrane. A study comparing home dialysis patients found that peritonitis accounted for roughly two-thirds of all severe infections in peritoneal dialysis patients. The risk of a severe infection during the first year was 35% for manual peritoneal dialysis (CAPD) and 25% for the machine-assisted version (APD).
Home hemodialysis patients had a lower overall infection rate, with an 11% risk of severe infection in the first year. However, bloodstream infections were more common in hemodialysis patients, making up 21% of their infection episodes compared to only 3% for peritoneal dialysis patients. Bloodstream infections tend to originate at the vascular access site, which is why meticulous hygiene around fistulas, grafts, and catheters is critical.
Regardless of modality, proper hand washing and sterile technique during connections and exchanges are the most effective ways to reduce infection risk.
Diet and Fluid Restrictions
Both forms of dialysis come with dietary rules, but hemodialysis patients generally face stricter limits because their treatment happens only three times a week, leaving waste and fluid to accumulate between sessions.
On hemodialysis, you’ll need to track your intake of potassium, phosphorus, sodium, and fluids carefully. That means limiting high-potassium foods like bananas, avocados, and dried fruit, and keeping phosphorus in check by cutting back on dairy (often capped at half a cup of milk per day), processed foods, nuts, and cola. Sodium restriction is important too, since excess salt drives thirst and fluid retention. Salt substitutes aren’t a safe workaround because they contain potassium. Even foods that are liquid at room temperature, like soup, gelatin, and ice cream, count toward your daily fluid goal.
Protein needs actually increase on hemodialysis. Dietitians recommend high-quality sources like meat, poultry, fish, and eggs because they produce less waste during digestion. A standard serving is about 3 ounces, roughly the size of your palm.
Peritoneal dialysis patients often have slightly more dietary freedom because treatment happens every day, so waste products don’t build up as much between sessions. Fluid restrictions tend to be more relaxed, though you still need to be mindful of your overall intake. However, because the dialysis fluid contains glucose and your body absorbs some of it, peritoneal dialysis patients need to watch their calorie and sugar intake more carefully, and blood sugar management becomes especially important if you have diabetes.
Who Can Choose Which Option
Most people with kidney failure can do either type of dialysis, but certain conditions may rule one out. Peritoneal dialysis may not be an option if you have extensive abdominal scarring from prior surgeries, a hernia, or digestive conditions like inflammatory bowel disease or frequent diverticulitis. You also need the manual dexterity to handle the catheter connections and fluid bags yourself, or a caregiver who can do it for you.
Hemodialysis can be more difficult for people with poor vascular access, meaning their veins are too small or damaged for a fistula or graft. It also requires reliable transportation to a dialysis center three times a week unless you’re set up for home hemodialysis, which has its own space and water-quality requirements.
Travel and Day-to-Day Flexibility
Peritoneal dialysis is generally easier to travel with. The supplies are portable, and APD machines are compact enough to take on a trip. You can perform exchanges in a hotel room or at a relative’s house without needing specialized infrastructure.
Traveling on hemodialysis takes more planning. Most patients arrange sessions at a dialysis center near their destination, a process called transient dialysis. Many dialysis centers have staff experienced in coordinating these visits. Some home hemodialysis patients travel with their machines and portable water treatment equipment, even dialyzing at campsites with electrical hookups, but this is uncommon. Wherever you go, it’s wise to know the location of the nearest dialysis center in case of an emergency.
Quality of Life Considerations
Systematic reviews consistently show that peritoneal dialysis patients report better health-related quality of life than hemodialysis patients. This likely reflects the greater independence, flexible scheduling, and ability to do treatment at home. Hemodialysis patients often report fatigue on treatment days and the burden of traveling to a center multiple times a week.
Survival outcomes between the two methods are broadly comparable, though results vary by region and patient population. Some studies show a slight early survival advantage for peritoneal dialysis, particularly in younger, healthier patients, while others find hemodialysis performs better over longer time horizons. The “right” choice depends less on survival statistics and more on your medical history, lifestyle, home situation, and personal preferences. Many nephrologists present both options and let patients weigh the tradeoffs for themselves.