Kidney failure is Stage 5 chronic kidney disease (CKD), defined by a glomerular filtration rate (GFR) below 15. GFR measures how much blood your kidneys filter per minute, and a healthy kidney scores 90 or above. To reach a Stage 5 diagnosis, your GFR must stay below 15 for at least three months, or you must already be on dialysis.
But kidney failure doesn’t happen suddenly. It’s the end point of a five-stage decline that can take years or even decades. Understanding where you or a loved one falls on that scale, and what each stage actually feels like, matters for knowing what comes next.
The Five Stages of Kidney Disease
Doctors classify kidney disease by how well your kidneys still filter blood. That filtering ability is expressed as your estimated GFR, or eGFR, calculated from a simple blood test that measures waste products your kidneys should be clearing.
- Stage 1 (GFR 90+): Your kidneys filter blood normally, but there are early signs of damage, usually protein leaking into your urine. Most people feel completely fine.
- Stage 2 (GFR 60–89): A mild drop in function with more evidence of damage. Still no symptoms for most people.
- Stage 3a (GFR 45–59): Mild to moderate loss of function. This is the most commonly diagnosed stage, and the point where some people first notice symptoms.
- Stage 3b (GFR 30–44): Moderate to severe loss. With proper treatment, many people stay at this stage and never progress to Stage 4.
- Stage 4 (GFR 15–29): Severe loss of function. Your kidneys are close to failing, and planning for dialysis or transplant typically begins here.
- Stage 5 (GFR below 15): Kidney failure. Your kidneys can no longer sustain your body’s needs. Dialysis or a transplant becomes necessary for most people.
Your GFR alone doesn’t tell the whole story. Doctors also check for protein (albumin) in your urine, because leaking protein signals kidney damage even when your GFR looks normal. The combination of these two numbers gives a more complete picture of how much trouble the kidneys are in and how quickly things might progress.
Why Most People Don’t Notice Early Stages
One of the most important things to understand about kidney disease is that it’s silent for a long time. Most people have no symptoms until the disease is advanced, often not until Stage 4 or 5. Your kidneys have so much built-in reserve capacity that they can lose more than half their function before you feel anything wrong.
When symptoms do appear, the first signs are often swelling in the hands and feet, itchy skin, or needing to urinate more frequently. As kidney function drops further, the list grows: fatigue, nausea, loss of appetite, trouble concentrating, muscle cramps, shortness of breath, and sleep problems. High blood pressure that becomes harder to control is another hallmark of advancing disease.
This is why kidney disease is frequently caught through routine blood work rather than symptoms. A standard metabolic panel can flag rising waste products in your blood, prompting a GFR calculation and urine test that reveal the problem.
What Happens at Stage 5
At Stage 5, your kidneys can no longer remove enough waste, balance fluids, or maintain the chemical equilibrium your body depends on. Waste products build up in the blood, a condition called uremia. The symptoms of uremia are hard to ignore: severe nausea and vomiting, mental confusion, visual disturbances, intense itching, muscle cramps, and profound fatigue. In rare cases, urea crystals can even appear on the skin as a white, frost-like residue.
When these signs appear, dialysis becomes necessary regardless of the exact GFR number. The goal is to take over the work your kidneys can no longer do: filtering waste, removing excess fluid, and restoring electrolyte balance.
Treatment Options for Kidney Failure
There are three paths once you reach Stage 5: dialysis, a kidney transplant, or supportive (palliative) care.
Dialysis comes in two forms. Hemodialysis filters your blood through a machine, typically at a clinic several times a week. Peritoneal dialysis uses the lining of your abdomen as a natural filter and can often be done at home. Both do the same basic job: clearing waste and excess fluid that your kidneys no longer handle.
A kidney transplant is generally considered the preferred option over lifelong dialysis. It involves receiving a healthy kidney from a living or deceased donor. The process takes time because finding a well-matched donor is critical, and the wait for a deceased-donor kidney can stretch for years depending on your region and blood type.
Some people, particularly those with other serious health conditions, choose supportive care instead. This focuses on managing symptoms and maintaining quality of life without dialysis or transplant. Palliative care can also be combined with dialysis or transplant planning to help with symptom relief along the way.
How CKD Is Diagnosed
A single low GFR reading doesn’t automatically mean you have chronic kidney disease. The diagnosis requires that either your GFR stays below 60 or you show signs of kidney damage (such as protein in the urine) for more than three months. Repeat testing is important to rule out temporary drops caused by dehydration, medication effects, or acute kidney injury, which can look similar on a single blood draw but has very different treatment and outcomes.
The current standard for estimating GFR uses a formula called CKD-EPI 2021, which calculates your kidney function based on a blood creatinine level, your age, and your sex. Notably, the 2021 version removed a previously used race-based adjustment, making the calculation the same for all patients.
Slowing Progression Between Stages
Kidney disease doesn’t always march straight from Stage 1 to Stage 5. Many people stay at Stage 3 for years, and some never progress further. The factors that speed up decline are largely the same ones that cause kidney damage in the first place: uncontrolled high blood pressure, poorly managed diabetes, and ongoing kidney inflammation.
Keeping blood pressure and blood sugar within target ranges is the single most effective way to slow progression. Reducing salt intake, staying physically active, avoiding medications that stress the kidneys (like frequent use of certain over-the-counter pain relievers), and not smoking all contribute to preserving the function you still have. The earlier these changes happen, the more kidney function they protect.