Chronic Kidney Disease Stages: 10 Critical Facts

Updated on: October 18, 2026
Written by: Adel Galal
Medical review status: This article has not been medically reviewed by a nephrologist, physician, renal dietitian, pharmacist, or other licensed healthcare professional.

Chronic kidney disease stages describe how well the kidneys filter blood and how much kidney damage is present.

The main blood test is eGFR. The main urine test is UACR, which checks for albumin in urine.

These two numbers work together. A person with a fairly good eGFR but a high urine albumin level can still have a high risk of kidney disease progression.

CKD is usually confirmed only when abnormal kidney findings have been present for at least three months.

This article is for general information and education. It does not replace medical advice, diagnosis, or treatment.

For a full overview, read Chronic Kidney Disease. For broader kidney information, see Kidney Disease and Kidney Disease Treatment.

How Do Chronic Kidney Disease Stages Work?

Chronic kidney disease stages are based on more than one number.

Doctors look at:

• The cause of kidney disease
• The GFR category
• The albuminuria category

This is called CGA classification.

The G category shows filtration. The A category shows how much albumin leaks into urine.

10 Critical Facts About CKD Stages

1. CKD Must Be Present for at Least Three Months

The word chronic means the problem persists.

CKD is usually diagnosed when reduced kidney function or another marker of kidney damage lasts for more than three months.

A temporary drop in eGFR during illness does not automatically mean CKD.

2. eGFR Sets the G Category

eGFR estimates how well the kidneys filter blood.

The G categories are:

• G1
• G2
• G3a
• G3b
• G4
• G5

Lower eGFR generally means lower kidney filtration.

3. UACR Sets the Albumin Category

UACR means urine albumin to creatinine ratio.

It checks how much albumin is leaking through the kidney filters.

The albumin categories are:

• A1
• A2
• A3

4. G1 and G2 Alone Do Not Prove CKD

This is a common source of confusion.

G1 means eGFR is 90 or higher.

G2 means eGFR is 60 to 89.

These categories only count as CKD when another marker of kidney damage is present, such as albuminuria or a structural kidney abnormality.

5. G3 Is Split Into G3a and G3b

G3 covers a wide range of kidney function, so it is divided into two groups.

G3a means eGFR 45 to 59.

G3b means eGFR 30 to 44.

The risk of complications and progression is usually higher in G3b.

6. Symptoms Do Not Define Your Stage

You cannot tell your CKD stage by how you feel.

Some people with G3 or even G4 disease have few symptoms.

Other people may feel unwell because of anemia, heart disease, infection, diabetes, or another condition even when kidney disease is less advanced.

7. Albuminuria Changes Risk

Two people with the same eGFR can have very different risks.

A person with A3 albuminuria generally has a higher risk of:

• Kidney function decline
• Kidney failure
• Heart disease
• Cardiovascular events

This is why eGFR should not be interpreted alone.

8. Small eGFR Changes Can Be Normal

eGFR can move a little from one test to another.

Possible reasons include:

• Hydration
• Acute illness
• Medicine changes
• Laboratory variation
• Changes in creatinine production

The trend over time is often more useful than one result.

9. G5 Does Not Always Mean Dialysis Starts Immediately

G5 means eGFR is below 15.

It is classified as kidney failure, but dialysis timing depends on the full clinical picture.

Doctors also consider:

• Fluid overload
• High potassium
• Acid buildup
• Uremic symptoms
• Nutrition
• Overall health

10. Care Becomes More Intensive as Risk Rises

As eGFR falls or albuminuria rises, monitoring often becomes more frequent.

Care may include:

• Medicine review
• Blood pressure control
• Diabetes care
• Potassium monitoring
• Anemia testing
• Bone and mineral testing
• Nephrology referral
• Kidney failure planning

CKD GFR Categories at a Glance

Stage G1 CKD

G1 means eGFR is 90 or higher.

This is not CKD by itself.

Another marker of kidney damage must usually be present.

Examples include:

• Albuminuria
• Blood in urine from a kidney cause
• Structural abnormalities
• Inherited kidney disease
• Kidney transplant history

Symptoms in G1

Most people have no symptoms.

Care in G1

Care focuses on treating the cause, controlling blood pressure, managing diabetes when present, reducing albuminuria, and protecting long term kidney and heart health.

Stage G2 CKD

G2 means eGFR is 60 to 89.

Like G1, G2 needs another marker of kidney damage before it meets CKD criteria.

Symptoms in G2

Symptoms are usually absent.

Care in G2

Important goals include:

• Blood pressure control
• Diabetes care
• UACR monitoring
• Medicine review
• Reducing cardiovascular risk

Stage G3a CKD

G3a means eGFR is 45 to 59 for at least three months.

This represents mild to moderate loss of kidney filtration.

Possible symptoms

Many people still have no clear symptoms.

Others may notice:

• Fatigue
• Mild swelling
• Changes in urine
• Higher blood pressure

These symptoms are not specific to G3a.

Care in G3a

Care may include:

• Regular eGFR monitoring
• UACR monitoring
• Blood pressure control
• Diabetes treatment
• Kidney protective medicines when appropriate
• Medicine dose review

Stage G3b CKD

G3b means eGFR is 30 to 44.

Kidney function is more reduced than in G3a.

Possible symptoms

Some people may notice:

• Fatigue
• Swelling
• Muscle cramps
• Poor appetite
• Itching

Others may still feel fairly well.

Care in G3b

Monitoring often becomes more detailed.

Doctors may check for:

• Anemia
• Potassium problems
• Acid buildup
• Calcium and phosphorus changes
• Medicine dose adjustments

Stage G4 CKD

G4 means eGFR is 15 to 29.

This represents severe reduction in kidney filtration.

Possible symptoms

Symptoms become more common and may include:

• Fatigue
• Swelling
• Loss of appetite
• Nausea
• Itching
• Muscle cramps
• Sleep problems
• Shortness of breath

Care in G4

Care may include:

• Nephrology follow up
• Closer potassium monitoring
• Anemia management
• Bone and mineral testing
• Nutrition review
• Kidney failure risk assessment
• Dialysis and transplant education

Stage G5 CKD

G5 means eGFR is below 15 and is classified as kidney failure.

This does not mean every person starts dialysis the same day.

Possible symptoms

Symptoms may include:

• Severe fatigue
• Swelling
• Shortness of breath
• Nausea
• Vomiting
• Loss of appetite
• Itching
• Muscle cramps
• Sleep problems
• Confusion

Care in G5

Options may include:

• Hemodialysis
• Peritoneal dialysis
• Kidney transplant
• Conservative kidney management in selected people

Albuminuria Categories A1 to A3

Why Albuminuria Can Change the Meaning of a CKD Stage

A person with G2 and A3 disease may have a higher progression risk than another person with G3a and A1.

That is why stage alone does not tell the whole story.

Risk depends on:

• Cause of CKD
• eGFR
• Albuminuria
• Diabetes
• Blood pressure
• Heart disease
• Rate of eGFR decline

Symptoms by CKD Stage

Symptoms are not reliable enough to assign a stage. Blood and urine tests are needed.

What Tests Are Used to Stage CKD?

Key tests include:

• Serum creatinine
• eGFR
• UACR

Other tests may include:

• Urinalysis
• Cystatin C
• Potassium
• Bicarbonate
• Calcium
• Phosphorus
• Complete blood count
• Kidney ultrasound
• Kidney biopsy in selected cases

Why Repeat Testing Matters

CKD is chronic.

That means repeat testing helps confirm that abnormalities are persistent rather than temporary.

A low eGFR can improve when the cause was:

• Dehydration
• Acute infection
• Low blood pressure
• A medicine effect
• Urinary blockage

How Often Should CKD Be Monitored?

There is no one schedule for everyone.

Monitoring frequency depends on:

• G category
• A category
• Rate of decline
• Diabetes
• Blood pressure
• Medicine changes
• Complications

Higher risk CKD generally needs closer monitoring.

What Does CKD Progression Mean?

CKD progression means kidney function is getting worse over time.

Warning patterns can include:

• Falling eGFR
• Rising UACR
• More difficult blood pressure control
• More CKD complications

Small changes do not always mean true progression, so trends should be interpreted carefully.

Can CKD Stage Improve?

Sometimes eGFR improves enough for the G category to change.

This can happen when a reversible problem is corrected.

However, established chronic structural kidney damage may still remain.

A better eGFR does not automatically mean CKD has disappeared.

Stage Based Treatment

CKD care becomes more intensive as risk rises.

Possible treatments include:

• Blood pressure control
• Diabetes management
• ACE inhibitors or ARBs when appropriate
• SGLT2 inhibitors when appropriate
• Selected mineralocorticoid receptor antagonists
• Statins
• Anemia treatment
• Acidosis treatment
• Bone and mineral care

Blood Pressure Control at Every Stage

Blood pressure control can slow kidney damage and reduce heart risk.

A kidney care plan may include:

• Prescribed medicines
• Lower sodium intake
• Physical activity
• Weight management when appropriate
• Home blood pressure monitoring

Diabetes Care at Every Stage

Diabetes is a major cause of CKD.

Care may include:

• Individual glucose targets
• Blood pressure control
• SGLT2 inhibitors when suitable
• Other glucose lowering medicines
• Regular UACR testing
• Regular eGFR testing

Read Diabetes and Kidney Disease.

Does Diet Change With CKD Stage?

Yes, but there is no one fixed renal diet.

Nutrition depends on:

• G stage
• A stage
• Blood potassium
• Phosphorus
• Blood pressure
• Diabetes
• Dialysis status
• Body weight
• Nutrition status

Read Diet for Kidney Disease.

Should Protein Be Reduced?

Very high protein intake may not be appropriate in nondialysis CKD.

However, too little protein can cause muscle loss and malnutrition.

People receiving dialysis often need more protein.

Should Potassium Be Restricted?

Not automatically.

Potassium restriction depends on:

• Blood potassium
• Medicines
• CKD stage
• Dialysis
• Other medical conditions

Should Phosphorus Be Restricted?

Not everyone needs a low phosphorus diet.

Restriction is more likely when blood phosphorus rises or advanced CKD affects bone and mineral balance.

How Much Water Should Someone With CKD Drink?

There is no universal amount.

Fluid needs depend on:

• Urine output
• Swelling
• Heart function
• Dialysis
• Climate
• Activity

Drinking extra water does not repair chronic kidney damage.

When Should a Nephrologist Be Involved?

Kidney specialist care may be helpful with:

• G4 or G5 CKD
• Rapid eGFR decline
• Heavy albuminuria
• Recurrent high potassium
• Resistant high blood pressure
• Blood in urine from a suspected kidney cause
• Inherited kidney disease
• Unclear CKD cause
• High kidney failure risk

What Is the Kidney Failure Risk Equation?

The Kidney Failure Risk Equation, or KFRE, estimates the risk that selected people with CKD will need kidney replacement therapy in the future.

It commonly uses:

• Age
• Sex
• eGFR
• Urine ACR

The result can help guide referral and planning.

When Should Dialysis Planning Start?

Planning should begin before a crisis.

Advanced CKD care may include education about:

• Hemodialysis
• Peritoneal dialysis
• Kidney transplantation
• Conservative kidney management

Planning early gives people more time to understand their options.

When Is Dialysis Actually Started?

Dialysis is not started from eGFR alone.

Reasons may include:

• Severe fluid overload
• Dangerous high potassium
• Severe acidosis
• Uremic symptoms
• Pericarditis
• Severe nausea or vomiting
• Progressive malnutrition

Can CKD Stages Predict Life Expectancy?

Not by themselves.

Life expectancy depends on much more than the G stage.

Important factors include:

• Age
• Cause of CKD
• Albuminuria
• Heart disease
• Diabetes
• Blood pressure
• Rate of progression
• Other medical conditions

Do not use a CKD stage alone to predict how long a person will live.

Common Myths About CKD Stages

Conclusion: Understand Chronic Kidney Disease Stages in Context

Chronic kidney disease stages are useful, but the G number alone does not tell the whole story.

Know both your eGFR and UACR. Ask what your G category and A category mean together, how fast your kidney function is changing, and whether your treatment is reducing progression risk.

Early stages may have no symptoms, while later stages need closer monitoring for anemia, potassium problems, bone changes, fluid overload, and kidney failure.

The goal is not simply to watch the stage. It is to protect kidney function, reduce heart risk, and plan ahead when risk rises.

References and Sources

1. KDIGO. 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease.
   Covers CKD definition, CGA classification, GFR categories, albuminuria, risk prediction, monitoring, progression, treatment, and kidney failure planning.
   https://kdigo.org/guidelines/ckd-evaluation-and-management/
2. National Kidney Foundation. How to Classify CKD.
   Covers G1 through G5 and A1 through A3 categories and explains why G1 and G2 need another marker of kidney damage.
   https://www.kidney.org/how-to-classify-ckd
3. National Kidney Foundation. Stages of Chronic Kidney Disease.
   Explains stage G1 through G5, eGFR, uACR, symptoms, and why testing needs to confirm long term kidney damage.
   https://www.kidney.org/kidney-topics/stages-chronic-kidney-disease-ckd
4. NIDDK. Chronic Kidney Disease Tests and Diagnosis.
   Covers eGFR, urine albumin testing, UACR, repeat testing, and how kidney disease is monitored.
   https://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/tests-diagnosis
5. NIDDK. Identify and Evaluate Patients With Chronic Kidney Disease.
   Covers CKD diagnosis, eGFR below 60, albuminuria, staging, chronicity, and risk evaluation.
   https://www.niddk.nih.gov/health-information/professionals/clinical-tools-patient-management/kidney-disease/identify-manage-patients/evaluate-ckd
6. NIDDK. Quick Reference on UACR and GFR.
   Explains why both urine albumin and eGFR are key markers of chronic kidney disease and progression risk.
   https://www.niddk.nih.gov/health-information/professionals/advanced-search/quick-reference-uacr-gfr

Internal Links and Helpful NextFitLife Guides

• Chronic Kidney Disease
• Kidney Disease
• Kidney Disease Treatment
• Kidney Disease Symptoms
• Diabetes and Kidney Disease
• Kidney Healthy Foods
• Diet for Kidney Disease
• How to Protect the Kidneys
• DASH Diet
• NextFitLife Health Hub

Frequently Asked Questions

What are the chronic kidney disease stages?

Chronic kidney disease uses GFR categories G1, G2, G3a, G3b, G4, and G5. Risk is also classified with albuminuria categories A1, A2, and A3.

What is stage G1 CKD?

G1 means eGFR is 90 or higher. It only counts as CKD when another marker of kidney damage is present.

What is stage G2 CKD?

G2 means eGFR is 60 to 89. Another marker of kidney damage is needed for it to meet CKD criteria.

What is stage G3a CKD?

G3a means eGFR is 45 to 59 for at least three months and represents mild to moderate loss of kidney filtration.

What is stage G3b CKD?

G3b means eGFR is 30 to 44 and represents moderate to severe loss of kidney filtration.

What is stage G4 CKD?

G4 means eGFR is 15 to 29 and represents severe reduction in kidney filtration.

What is stage G5 CKD?

G5 means eGFR is below 15 and is classified as kidney failure.

Does G5 always mean immediate dialysis?

No. Dialysis timing depends on symptoms, fluid overload, potassium, acid balance, nutrition, and other complications, not eGFR alone.

What is albuminuria?

Albuminuria means albumin is leaking into urine. It is commonly measured with the urine albumin to creatinine ratio, or UACR.

What is A1 albuminuria?

A1 means UACR is below 30 mg/g and is classified as normal to mildly increased.

What is A2 albuminuria?

A2 means UACR is 30 to 300 mg/g and is classified as moderately increased.

What is A3 albuminuria?

A3 means UACR is above 300 mg/g and is classified as severely increased.

Can you tell your CKD stage from symptoms?

No. CKD stage is based on kidney tests, not symptoms. Early and middle stage disease may cause few or no symptoms.

Does one low eGFR mean chronic kidney disease?

No. CKD usually requires abnormalities that persist for at least three months unless there is clear evidence that kidney damage is already chronic.

Can eGFR improve?

Yes. eGFR can improve if a reversible problem such as dehydration or acute illness is corrected, although chronic kidney damage may still remain.

Is eGFR a percentage?

No. eGFR is an estimate of filtration reported in milliliters per minute per 1.73 square meters, not a direct percentage of kidney function.

Why does UACR matter if eGFR is normal?

Albuminuria can show kidney damage even when filtration is still preserved and can raise the risk of CKD progression and cardiovascular disease.

When should a person with CKD see a nephrologist?

Specialist care is often useful with G4 or G5 CKD, rapid eGFR decline, heavy albuminuria, recurrent high potassium, resistant blood pressure, inherited disease, or an unclear cause.

Can CKD stages improve with treatment?

Kidney function can stabilize or improve in some people, especially when reversible factors are treated, but established chronic kidney damage may not fully reverse.

Do CKD stages predict life expectancy?

Not by themselves. Age, albuminuria, heart disease, diabetes, the cause of CKD, and the rate of progression also strongly affect risk.