Dialysis does not always work, and how well it works varies widely from person to person. The five-year survival rate after starting maintenance dialysis is approximately 40 percent, meaning the treatment sustains life for many people but has real limits. Whether dialysis “works” depends on what you mean: it can effectively filter waste from the blood in a single session, but it cannot fully replicate what healthy kidneys do around the clock.
What “Working” Actually Means
Doctors measure whether dialysis is doing its job by checking how much waste it removes from the blood during each session. The main target is a urea reduction of at least 65 percent per treatment for patients on a standard three-times-per-week schedule. When that threshold is met consistently, the treatment is considered adequate from a clinical standpoint.
But adequate waste clearance on paper doesn’t always translate to feeling well. Dialysis patients as a group report significantly lower physical quality of life compared to the general population, scoring roughly 35 out of 100 on standardized physical health surveys at the time they start treatment. That score doesn’t improve dramatically over time. Common ongoing symptoms include fatigue, nausea, lightheadedness, difficulty concentrating, and leg swelling. Younger patients tend to report more emotional symptoms like sadness, anxiety, and irritability, while older patients are more likely to experience physical symptoms like swelling.
Reasons Dialysis Can Fall Short
Several things can undermine how well dialysis works for a given person. The most common technical problem is failure of the vascular access point, the surgically created connection in the arm where blood flows to and from the dialysis machine. These access points can narrow, clot, become infected, or develop bulges over time. When access fails, treatment is interrupted until a new connection can be established, which sometimes means temporary, less effective alternatives.
The treatment itself can also cause problems. A condition called dialysis disequilibrium syndrome occurs when waste products are cleared from the blood faster than they can leave the brain, creating a temporary fluid imbalance that causes swelling in brain tissue. Symptoms range from headaches, nausea, and blurred vision to, in rare severe cases, seizures or loss of consciousness. This is most common during the first few dialysis sessions and usually resolves within hours, but it illustrates that the process of filtering blood artificially carries its own risks.
Potassium imbalances during treatment can cause the heart to beat irregularly. Rapid fluid removal often triggers nausea, cramping, and drops in blood pressure. Over time, inadequate dialysis can lead to inflammation around the heart, which interferes with its ability to pump blood effectively.
Hemodialysis vs. Peritoneal Dialysis
The two main types of dialysis don’t perform identically. Hemodialysis filters blood through an external machine, typically at a clinic three times a week. Peritoneal dialysis uses the lining of your abdomen as a natural filter and can be done at home, often daily.
Research comparing the two approaches found that peritoneal dialysis produced better waste clearance, lower blood pressure, and better heart pumping efficiency. Hemodialysis, on the other hand, was better at maintaining protein levels in the blood, which matters for nutrition and healing. Neither method is universally superior. The best choice depends on your overall health, living situation, and which complications you’re most at risk for.
Age and Other Health Conditions Matter
Dialysis outcomes are heavily shaped by what else is going on in your body. For people over 75 with multiple serious health conditions, particularly heart disease, there is evidence that dialysis may not actually extend life compared to not receiving it at all. This is one of the most important and least discussed realities of the treatment.
Age alone doesn’t determine outcomes as much as you might expect. Older patients actually report slightly better mental health and lower symptom burden during their first year on dialysis compared to younger patients. But when symptoms do increase, older patients experience a steeper decline in physical health than younger ones, suggesting they have less physiological reserve to absorb the stress of treatment.
How Dialysis Compares to Transplant
For patients who are eligible, a kidney transplant dramatically outperforms long-term dialysis. Even among people over 70, transplant recipients had 38 percent lower mortality than those who stayed on dialysis. Five-year survival was 80 percent for transplant recipients compared to 53 percent for matched dialysis patients in the same age group. A transplant isn’t an option for everyone, but when it is, the survival advantage is substantial.
When Dialysis Stops Working or Isn’t Chosen
Some patients reach a point where dialysis no longer controls their symptoms, or where the burden of treatment outweighs its benefits. Others, after learning about the process, choose not to start dialysis at all. In some specialized kidney clinics, as many as one in six patients now choose this path. These patients tend to be elderly with several other serious illnesses.
Choosing conservative care without dialysis doesn’t mean choosing no care. Patients still receive monitoring of kidney function, treatment for anemia to reduce fatigue, dietary guidance, and focused symptom management. They often continue living with very low kidney function for months, though approximately 75 percent die within a year. Kidney function at the time of death is typically around 5 milliliters per minute, a tiny fraction of normal.
For patients who withdraw from dialysis after already being on it, the timeline is much shorter. Average survival after stopping treatment is 8 to 11 days, which is why planning for end-of-life care ideally begins before the decision is made to stop.