When dialysis is needed: symptoms, not just numbers

The evidence that changed the question

For years, the working assumption in kidney medicine was that starting dialysis earlier must be better. Waste is accumulating, so remove it sooner. It is an intuitive idea, and in 2010 somebody finally tested it properly.

The IDEAL trial randomised 828 adults with advanced, progressive kidney disease to either an early start (at an eGFR of 10 to 15) or a late start (at an eGFR of 5 to 7). The result was published in the New England Journal of Medicine, and it was unambiguous: there was no significant difference in death rates, and no significant difference in any clinically important secondary outcome either. Not cardiovascular events. Not infection. Not hospital admissions. Not quality of life.

Two details from that trial matter enormously, and they usually get left out.

• The groups converged. The early group actually started at an average eGFR of about 12.0 and the late group at about 9.8, a gap of only around 2.2. The late group began dialysis a median of roughly six months later than the early group.
• About three quarters of the "late" group had to start before reaching the target window, because they developed symptoms. That is not a failure of the trial. It is the trial telling you what actually drives the decision.

What the guidelines actually say

They agree on the principle and differ a little on the ranges, which is worth knowing, because a clinician trained in one country may quote you a different figure from a website written in another.

KDIGO (international)

Start dialysis when symptoms or signs attributable to kidney failure appear. KDIGO notes this "often but not invariably" happens when the eGFR is somewhere between 5 and 10. The 2024 guideline frames the decision as a composite: symptoms, signs, quality of life, your preferences, the filtration rate, and the laboratory results, taken together.

NICE (United Kingdom)

NICE NG107 advises considering dialysis when it is indicated by the impact of uraemic symptoms on daily living, or by the blood results, or by fluid overload that cannot be controlled, or at an eGFR of around 5 to 7 if there are no symptoms at all. NICE also states that the decision must be made jointly by the person, their family or carers where appropriate, and the healthcare team.

KDOQI (United States)

The 2015 update went further than anyone: it removed the previous eGFR-based cut-offs entirely. The decision, it says, should rest primarily on the signs and symptoms of uraemia, on evidence of protein-energy wasting, and on whether the metabolic abnormalities and the fluid can still be managed safely, rather than on any specific level of kidney function.

European Renal Best Practice

The same principle, with an explicit warning against basing the decision on the estimated filtration rate alone.

The symptoms and signs that actually trigger it

Guidelines list these consistently. Some are gradual, and are a reason for a conversation. Some are urgent, and are a reason to start.

The uraemic symptoms

Nausea and vomiting. Loss of appetite. Weight loss. Fatigue that sleep does not repair. Itching. Restless legs. Broken sleep. Difficulty concentrating. A metallic taste. These build slowly, which is exactly the problem: people adapt to them, decide this is simply how they are now, and do not report them. Then they start dialysis, feel better within weeks, and say some version of "I did not realise how ill I had become". That sentence is one of the most common in nephrology.

The urgent indications

• Fluid overload that will not respond to water tablets: breathlessness, fluid on the lungs, blood pressure that cannot be controlled.
• Potassium or acid levels that cannot be brought back into a safe range.
• Inflammation of the lining of the heart or the lungs caused by uraemia. This is an urgent indication in every guideline.
• Uraemia affecting the brain: confusion, or a change in thinking that has no other explanation.
• Nutritional decline despite a dietitian's help. Starting dialysis to protect nutrition is a legitimate reason, and a badly under-used one.

How to think about it, honestly

Here is the framing we would offer, and it is the one clinicians use among themselves: the right time to start is when the illness is taking more from you than the treatment will.

Dialysis costs you something real. Time, energy, a schedule, a diet, needles or a tube, the washed-out feeling after a session. Nobody should pretend otherwise, and we do not. But advanced uraemia also costs you something real: appetite, sleep, thinking, muscle, and eventually life. The decision is about which of those two prices is currently higher, and only you can weigh that.

What you should refuse is the idea that this is being done to you. NICE is explicit that the decision is joint. You are entitled to ask: what would happen if I waited? What are you seeing in my results that concerns you? What would change your mind? And you are entitled to a real answer.

Preparing is not the same as starting

This is the single most useful thing on this page, and it is where people lose the most.

• NICE: start the assessment for dialysis, transplant or conservative care at least a year before it is likely to be needed.
• KDIGO: plan for treatment, including a pre-emptive transplant assessment or a dialysis access, when the eGFR falls below 15 to 20, or when the two-year risk of needing treatment is above 40%.
• A fistula takes months to become usable. Creating one is not a commitment to start dialysis tomorrow. It is a commitment to having a choice when the time comes.

People who prepare get to choose their treatment, get assessed for a transplant while there is still time to find a living donor, and start on a working fistula. People who do not prepare arrive in hospital unwell, start on a neck catheter (the access with the highest infection risk), have no time to consider peritoneal dialysis or conservative care, and often never get offered a real choice at all. The medicine is the same. The experience is not remotely the same.

So say yes to the referral, say yes to the access conversation, and say yes to the transplant assessment, even if you feel well. None of those is the start of dialysis. They are what keeps the decision in your hands.

When you are ready, the next thing worth understanding is what you are actually choosing between. There are four legitimate paths, and one of them is choosing not to dialyse at all: compare your options honestly.