Dialysis typically becomes necessary at stage 5 chronic kidney disease, when your kidneys are functioning at less than 15% of normal capacity. This corresponds to an estimated glomerular filtration rate (eGFR) below 15, a measure of how well your kidneys filter waste from your blood. But the number alone doesn’t tell the whole story. The decision to start dialysis depends heavily on how you feel and how your body is handling the buildup of waste products, not just on hitting a specific lab value.
What Stage 5 Kidney Disease Means
Chronic kidney disease is classified into five stages based on eGFR, which estimates the percentage of normal kidney function you still have. Stage 5, also called kidney failure or end-stage kidney disease (ESKD), is defined as an eGFR below 15 sustained for three months or more. At this point, your kidneys can no longer remove enough waste, balance fluids, or regulate essential minerals on their own. The National Kidney Foundation describes this as your kidneys working at less than 15% of what two healthy kidneys in a young person can do.
Most people move through stages 3 and 4 before reaching stage 5, though the timeline varies enormously. Some people live with stage 4 (eGFR 15 to 29) for years with careful management. Others progress more quickly, especially with uncontrolled diabetes or high blood pressure. Not everyone at stage 5 starts dialysis immediately. The timing depends on symptoms, lab results, and individual circumstances.
Symptoms That Trigger Dialysis
Dialysis is recommended for anyone experiencing symptomatic uremia, the condition where waste products build up in the blood to harmful levels, causing nausea, vomiting, persistent fatigue, confusion, or memory problems. These symptoms warrant starting dialysis regardless of what your eGFR number shows.
Certain situations require emergency dialysis:
- Severe acid buildup in the blood that medications can’t correct
- Dangerously high potassium (above 6.5 mEq/L), which can trigger life-threatening heart rhythm problems
- Fluid overload causing shortness of breath or heart failure that doesn’t respond to diuretics
- Uremic encephalopathy, where toxin buildup affects the brain, causing confusion, seizures, or loss of consciousness
- Uremic pericarditis, inflammation around the heart caused by waste products in the blood
A helpful way doctors remember these emergency triggers is the mnemonic AEIOU: Acidosis, Electrolytes (especially potassium), Ingestions (drug overdoses the kidneys can’t clear), Overload of fluid, and Uremia. Any of these can make dialysis immediately necessary, even in someone who wasn’t previously on a dialysis plan.
Why the GFR Number Isn’t Everything
For years, there was debate about whether starting dialysis earlier (at a higher eGFR) might help people live longer. A landmark trial published in the New England Journal of Medicine settled much of this debate. Researchers randomly assigned over 800 patients with stage 5 kidney disease to either early-start or late-start dialysis. After a median follow-up of nearly 3.6 years, survival rates were virtually identical: 37.6% of the early-start group died compared to 36.6% of the late-start group. Rates of cardiovascular events, infections, and dialysis complications were also similar between the two groups.
Notably, about 76% of the patients assigned to the late-start group ended up starting dialysis before reaching their target eGFR of 7.0, because symptoms developed that made waiting no longer safe. This reinforces the current approach: rather than starting at a fixed number, the best time to begin is when your body signals it can no longer compensate.
Acute Kidney Injury Is Different
Not all dialysis is for chronic kidney disease. Acute kidney injury, a sudden drop in kidney function from causes like severe infection, trauma, or medication toxicity, can also require dialysis. In these cases, dialysis is often temporary. The kidneys may recover enough function over days or weeks that dialysis can stop.
The triggers for acute dialysis are similar: dangerously high potassium, severe acid levels in the blood (pH below 7.15), fluid overload that doesn’t respond to medication, or very low urine output sustained over 12 to 24 hours. A blood urea nitrogen level above 100 mg/dL is considered an absolute indication to start dialysis in acute cases. These patients are typically in a hospital setting, and the decision is made urgently rather than as part of a planned transition.
Preparing Before You Need Dialysis
If you’re in stage 4 kidney disease and progressing toward stage 5, your care team will likely begin preparing for dialysis well before you actually need it. For hemodialysis, this means creating a vascular access point, usually an arteriovenous fistula in the arm. This small surgical procedure connects an artery to a vein, allowing the fistula to strengthen and mature over several months. Nephrologists generally encourage fistula creation when hemodialysis appears likely within 12 months.
This preparation time is important. A mature fistula works better and carries fewer complications than emergency access through a temporary catheter. Planning ahead also gives you time to explore whether peritoneal dialysis (a home-based option that uses the lining of your abdomen to filter blood) or a kidney transplant might be a better fit for your life.
When Dialysis May Not Be the Right Choice
Dialysis is not the only path for every person with stage 5 kidney disease. Comprehensive conservative care, which focuses on managing symptoms and maintaining quality of life without dialysis, is a recognized alternative for some patients. Current guidelines recommend that doctors present this option particularly to older adults or those with serious additional health conditions, significant frailty, or limited functional independence.
Research consistently shows that patients who choose dialysis tend to be younger with fewer coexisting health problems, while those who opt for conservative care are generally older with more complex medical situations. Neither choice is categorically right or wrong. The decision involves weighing survival differences against quality of life, treatment burden, and personal goals. This is a conversation best had early, before an emergency forces the decision, so you can make a choice that aligns with what matters most to you.