Facts About Stages Of Kidney Failure

31 Mar 2022

7 Min. Read

Last updated on 09 Nov 2026

Understanding the stages of kidney failure can help people recognise changes in kidney function, seek medical attention early and make informed decisions about treatment.

Kidney disease often develops gradually, and a person may have very few symptoms in its early stages. As kidney damage progresses, the kidneys may struggle to remove waste products, balance fluids and maintain essential functions.

Chronic kidney disease (CKD) is classified into five main stages based on how well the kidneys filter blood. However, kidney failure does not always develop gradually. Acute kidney injury (AKI), also called acute renal failure, can cause a sudden decline in kidney function and requires prompt medical attention.

This guide explains the different kidney disease stages, their symptoms, how kidney function is measured and when to seek medical care.

Key Takeaways

Chronic kidney disease is classified into five stages based on kidney function and evidence of kidney damage.
eGFR is an important measurement used to assess kidney filtration and determine CKD stages.
Early kidney disease often causes no noticeable symptoms, making regular screening important for people at risk.
Stage 4 indicates severe kidney damage, while stage 5 represents kidney failure.
Acute kidney injury develops suddenly and may be reversible with timely treatment.
Dialysis and kidney transplantation are treatment options for advanced kidney failure, depending on individual needs.

The Function of Kidneys

The kidneys are two bean-shaped organs located on either side of the spine, just below the rib cage. They continuously filter the blood to remove waste products and excess fluid, which leave the body through urine.

When the kidneys become damaged, these functions may gradually decline. This can lead to a buildup of waste products, fluid retention and disturbances in the body's mineral balance.

The Stages of Kidney Failure

The stages of kidney failure generally refer to the five stages of chronic kidney disease. They are classified according to the estimated glomerular filtration rate (eGFR), which measures how effectively the kidneys filter waste from the blood.

An eGFR result is calculated using blood creatinine levels, along with factors such as age and sex, depending on the equation used. A lower eGFR generally indicates reduced kidney function.

According to the Kidney Disease: Improving Global Outcomes (KDIGO) classification, CKD is divided into five stages, from G1 to G5.

Five stages of chronic kidney disease

Stage 1: Early kidney damage: eGFR- 90 or higher

At this stage, kidney filtration is usually within the normal range, but tests may reveal early damage. For example, excess protein in the urine, blood in the urine or structural abnormalities may indicate kidney disease.

Most people do not experience noticeable symptoms. Early detection and treatment of underlying conditions, such as diabetes and high blood pressure, can help protect kidney function.

Stage 2: Mild reduction in kidney function

Kidney filtration is slightly reduced, but the kidneys can generally perform most of their essential functions.

Symptoms are usually absent or difficult to notice. However, persistent protein in the urine or other signs of kidney damage may be present.

Regular monitoring of blood pressure, blood glucose, eGFR and urine albumin levels is important to identify any progression.

Stage 3: Moderate reduction in kidney function

Stage 3 is divided into two categories:

Stage 3a: eGFR between 45 and 59.
Stage 3b: eGFR between 30 and 44.

At this stage, waste products may begin accumulating in the blood. Some people develop fatigue, swelling in the feet or ankles, changes in urination and anaemia.

Doctors may recommend dietary adjustments, medication and regular blood and urine tests to manage complications and slow further kidney damage.

Stage 4: Severe kidney damage

Stage 4 kidney disease indicates a significant reduction in kidney function, with an eGFR between 15 and 29.

At this stage, there are clear symptoms, so close monitoring by a nephrologist becomes particularly important.

Treatment focuses on managing complications and preparing for possible kidney replacement therapy, such as dialysis or transplantation, if needed.

Stage 5: Kidney failure

This is the most advanced stage of chronic kidney disease, with an eGFR below 15.

The kidneys have lost most of their filtering capacity, allowing waste products and excess fluid to accumulate in the body.

This can cause serious complications, including electrolyte imbalances, fluid overload and cardiovascular problems.

Symptoms may include severe fatigue, persistent nausea, loss of appetite, swelling, breathing difficulties, confusion and significantly reduced urine output.

Treatment options may include haemodialysis, peritoneal dialysis or kidney transplantation. However, dialysis is not automatically started based on eGFR alone. Doctors consider symptoms, laboratory findings, complications and the person's overall health when deciding when to begin treatment.

Signs and Symptoms of Kidney Problems

Kidney problem symptoms can vary depending on the underlying cause and the extent of kidney damage. Early kidney disease often develops without noticeable warning signs.

As kidney function declines, symptoms may include:

These symptoms do not necessarily mean someone has kidney failure. Other medical conditions can cause similar problems. Blood and urine tests are needed to establish the cause.

What Causes Kidney Damage?

Kidney damage can develop due to several underlying conditions. Some of the common causes include:

Diabetes: Persistently high blood glucose levels can damage the small blood vessels that filter blood in the kidneys.
High blood pressure: Uncontrolled hypertension can damage kidney blood vessels and gradually reduce filtration capacity.
Glomerulonephritis: Inflammation of the glomeruli, which are tiny filtering structures inside the kidneys.
Polycystic kidney disease: An inherited condition in which fluid-filled cysts develop in the kidneys.
Recurrent kidney infections: Repeated or severe infections may cause lasting kidney damage.
Urinary tract obstruction: Kidney stones, an enlarged prostate or other blockages can interfere with urine flow.
Certain medications: Prolonged or inappropriate use of certain medicines, including some non-steroidal anti-inflammatory medicines (NSAIDs), may contribute to kidney injury.

Dr. Vassalotti highlights the importance of identifying kidney damage before it progresses. Since early-stage chronic kidney disease may not cause noticeable symptoms, people with diabetes, high blood pressure or a family history of kidney disease should discuss regular kidney screening with their healthcare provider. Blood tests measuring eGFR and urine tests checking albumin can help detect kidney abnormalities early.

Conclusion

Although some forms of kidney damage cannot be reversed, appropriate treatment and lifestyle changes can help preserve the remaining kidney function.

Some important measures include:

Dietary requirements differ according to the stage of kidney disease, laboratory results and other medical conditions. A nephrologist or renal dietitian can help develop an appropriate plan.

FAQs

Q1. What is the creatinine level for stage 4 kidney disease?

There's no single serum creatinine that defines stage 4 CKD. Stage 4 is when the eGFR is between 15 and 29 mL/min/1.73m². Creatinine levels will of course vary according to age, sex, muscle mass and all the other things that affect it.

Q2. How do you know if you have kidney failure?

Kidney failure is identified through blood tests, particularly serum creatinine and eGFR, along with urine tests and sometimes imaging. Symptoms such as swelling, fatigue, reduced urine output and nausea may indicate kidney problems, but testing is necessary for diagnosis.

Q3. How many types of kidney disease are there?

There are numerous types of kidney disease, classified according to their causes and the part of the kidney that they affect. Examples of these include diabetic kidney disease, hypertensive kidney disease, glomerulonephritis, polycystic kidney disease and kidney infections.

Q4. Can kidney failure happen suddenly?

Yes, AKI can lead to a rapid fall in kidney function over hours or days. It can be due to severe dehydration, infection, blood loss, certain medications or urinary obstruction. It can sometimes be reversed with appropriate treatment.

Q5. Is stage 4 kidney disease reversible?

Stage 4 CKD is essentially CKD with permanent damage and is not usually reversible. It can be managed though by treating the underlying aetiology and managing the complications.

Q6. What are the signs of dying from kidney failure?

In advanced kidney failure that's not being treated you can have quite severe symptoms including extreme weakness, persistent nausea, loss of appetite, confusion, reduced consciousness, breathlessness and very little urine. The symptoms don't necessarily tell you how close someone is to death. Some of them may be treatable complications. If someone with kidney failure is getting very breathless, is confused, having seizures or is becoming less and less conscious, then you need to get them to A&E.

References

Medical Disclaimer: This article is intended for educational purposes only and should not replace professional medical advice, diagnosis or treatment. Consult a qualified healthcare professional for appropriate diagnosis and treatment.