The four types of dialysis are in-center hemodialysis, home hemodialysis, peritoneal dialysis, and continuous renal replacement therapy (CRRT). The first three are used for ongoing kidney failure, while CRRT is reserved for critically ill patients in the hospital. In-center hemodialysis is by far the most common, accounting for about 57% of all people living with end-stage kidney disease in the United States as of 2023.
In-Center Hemodialysis
In-center hemodialysis is the standard form of dialysis most people picture. You travel to a dialysis clinic three times per week, where a machine draws your blood through a filter that removes waste products and excess fluid, then returns the cleaned blood to your body. Each session lasts three to four hours.
To connect you to the machine, you need a type of access point in your body. The preferred option is a fistula, a surgical connection between an artery and a vein (usually in the arm) that creates a strong, durable access point with low infection risk. However, fistulas take one to four months to mature before they can be used. A synthetic graft is another option that can be used sooner after surgery but doesn’t last as long. For patients who need dialysis urgently, a catheter placed in a large vein serves as a temporary bridge.
The main advantage of in-center hemodialysis is that trained staff handle everything. You show up, sit in a chair, and the clinical team monitors the treatment. The trade-off is a rigid schedule that revolves around your appointments, plus travel time to and from the center. Dietary restrictions also tend to be stricter with this type, particularly around fluid, potassium, and phosphorus intake between sessions. In the U.S. and Canada, many clinics also limit eating during treatment itself.
Home Hemodialysis
Home hemodialysis uses the same basic technology as in-center treatment, but you perform it yourself (or with a care partner) using a smaller machine at home. This gives you far more flexibility in scheduling. Some people do shorter sessions more frequently, such as five or six times per week, while others opt for longer overnight sessions.
More frequent treatments can mean gentler fluid removal and fewer of the blood pressure swings that sometimes happen during standard three-times-a-week sessions. You still need a vascular access point, just like in-center patients, and you’ll go through training before starting.
Despite these advantages, home hemodialysis remains rare. Only about 1.7% of people with established kidney failure in the U.S. use it. The learning curve, the need for a reliable care partner in many programs, and the responsibility of managing equipment at home are real barriers for many patients.
Peritoneal Dialysis
Peritoneal dialysis works on a completely different principle. Instead of filtering blood through a machine, it uses the lining of your abdomen (the peritoneum) as a natural filter. A soft catheter is surgically placed in your abdomen, and through it you fill your abdominal cavity with a sterile cleansing fluid. Waste products and extra fluid pass from your blood vessels into this fluid, which you then drain and replace.
There are two forms. Continuous ambulatory peritoneal dialysis (CAPD) is done manually. You perform exchanges throughout the day, typically four times, using a simple bag system. Each exchange involves draining the used fluid and filling with fresh solution through a single connection and disconnection. Automated peritoneal dialysis (APD) uses a machine called a cycler that performs multiple shorter exchanges overnight while you sleep, usually over eight to ten hours, sometimes with an additional daytime fill.
About 8% of U.S. patients with established kidney failure use peritoneal dialysis. It offers more independence and doesn’t require needles or vascular access, which appeals to many people. Peritoneal dialysis patients tend to have more potassium removed continuously, which can actually lead to low potassium levels. A large study of over 120,000 dialysis patients found that those on peritoneal dialysis were 3.3 times more likely to have low potassium compared to hemodialysis patients, and both extremely low and high potassium levels carry health risks. So dietary guidance differs: peritoneal dialysis patients may actually need to eat more potassium-rich foods rather than restrict them.
Some research suggests peritoneal dialysis may be associated with a lower mortality risk compared to hemodialysis, though the evidence isn’t strong enough to draw firm conclusions. Quality of life factors, like schedule flexibility and the ability to travel more easily, often weigh heavily in the decision.
Continuous Renal Replacement Therapy
CRRT is fundamentally different from the other three types because it’s not a long-term treatment you choose. It’s used in intensive care units for patients who are too unstable to tolerate regular hemodialysis. When someone is critically ill, perhaps from sepsis, severe organ failure, or major trauma, their blood pressure may be too fragile for standard hemodialysis, which removes fluid relatively quickly over a few hours.
CRRT works slowly and continuously, often running 24 hours a day. This gradual approach allows for controlled fluid removal without the sharp drops in blood pressure that faster treatments can cause. It’s particularly useful for patients with brain swelling, because it removes waste products gently enough to avoid dangerous pressure changes inside the skull. It also helps manage patients whose bodies are breaking down large amounts of tissue rapidly, such as in severe muscle injury or certain cancer treatment complications.
There’s some evidence that CRRT can also filter out inflammatory molecules involved in sepsis, potentially helping manage widespread infection and organ failure. Once a patient stabilizes, they’re typically transitioned to standard hemodialysis or, if kidney function doesn’t recover, evaluated for long-term dialysis options.
How To Think About Choosing a Type
For most people facing dialysis, the real decision is between in-center hemodialysis, home hemodialysis, and peritoneal dialysis. CRRT isn’t something you opt into; it’s used when the clinical situation demands it. The choice among the other three depends on your medical situation, your lifestyle, and what matters most to you.
In-center hemodialysis requires the least self-management but the most time commitment to a fixed schedule. Home hemodialysis offers flexibility but requires training, equipment space, and often a care partner. Peritoneal dialysis avoids needles entirely and fits more easily around work or travel, but requires daily commitment to exchanges and careful hygiene around the abdominal catheter to prevent infection.
Dietary restrictions also shift depending on the type. Hemodialysis patients typically face tighter limits on fluid, potassium, and phosphorus between sessions. However, overly strict restrictions aren’t always beneficial. Research has shown that among hemodialysis patients, higher fluid intake between sessions was actually associated with better nutritional status and even a trend toward better survival, likely because it reflected adequate food and protein intake. The key is balancing restriction with adequate nutrition, especially for patients who still produce some urine on their own.
Not every type is available to every patient. Your remaining kidney function, other medical conditions, abdominal surgery history, home environment, and personal support system all factor in. Many kidney programs will walk you through the options well before you need to start, giving you time to prepare the right access point and make a decision that fits your life.