What are the Chronic Kidney Disease Stages?

Chronic Kidney Disease Stages 

When an individual's kidney fails to filter the blood properly and gets damaged, it is termed chronic kidney disease. Doctors recommend blood and urine tests to check the patient's eGFR (estimated glomerular filtration rate) and uACR (albumin-to-creatinine ratio), respectively. This helps detect the severity of kidney damage, enabling healthcare providers to suggest the required treatment methods accordingly. 

Chronic kidney disease is defined as abnormalities of kidney structure or function, present for at least 3 months, with implications for health, including reduced eGFR and/or markers of kidney damage such as albuminuria. 

 
Read on to learn about chronic kidney disease (CKD) stages, its symptoms, causes and more.  

What are the 5 Categories of Chronic Kidney Disease? 

 
Depending on your eGFR value, CKD is classified into 5 stages. Here are they: 

Stage 1 CKD
  

During Stage 1 CKD, the eGFR is 90 or more, which shows that the kidneys are functioning normally with minor damage. Patients are usually asymptomatic, but some tests can detect kidney damage through the presence of protein in urine via a urine albumin-to-creatinine ratio (ACR) test.  

 
The kidneys should be monitored regularly to assess their condition. 

Stage 2 CKD

 
Stage 2 CKD is characterized by an eGFR between 60 and 89, with mild kidney damage. Similar to Stage 1, individuals may not exhibit symptoms but could have protein in their urine or other indicators of kidney damage. Continued monitoring and lifestyle changes can help manage the condition. 

Note: Both stage 1 and 2 CKD require evidence of kidney damage (such as albuminuria, structural abnormalities, or histological findings) despite normal or mildly reduced eGFR. 

 Stage 3 CKD

 
At this point, eGFR is between 30 and 59, which shows mild to moderate kidney damage. The kidneys start to have difficulty filtering waste, which can cause health problems such as high blood pressure and bone disease. Symptoms such as fatigue and swelling in the feet or hands might begin to develop. Stage 3 is also divided into two substages: 

• Stage 3a: eGFR of 45 to 59
• Stage 3b: eGFR of 30 to 44 

 
Most patients can avoid progression to advanced stages with proper treatment and lifestyle changes. 

Stage 4 CKD

 
In Stage 4 CKD, the eGFR ranges from 15 to 29, indicating moderate to severe damage to the kidneys. It is characterized by severe difficulty while filtering out waste, with elevated risks of developing complications like heart disease and bone disease.  

 
Stage 4 CKD may be associated with symptoms such as fatigue, edema, nausea, anorexia, and metabolic complications. This stage is crucial because it is a precursor to kidney failure. Hence, frequent nephrologist visits are essential in planning possible treatments such as dialysis or transplants. 

Stage 5 CKD

 
Stage 5 CKD represents severe kidney damage with an eGFR of under 15. Stage 5 CKD represents kidney failure (eGFR <15 ml/min/1.73 m²), with or without the need for dialysis. They may present with extreme fatigue, nausea, and swelling. Treatment options here are generally dialysis or a kidney transplant to treat life-threatening complications. 

Overview of CKD Stages Based on eGFR Values 

 
Apart from these 5 stages, there are three more stages based on the albumin-to-creatinine ratio of an individual's kidney. They are as follows: 

A1: Normal to Mildly Elevated Levels

 
During this phase, urine protein is below 30 mg/g or 3 mg/mmol, and the kidneys function normally with minimal damage. Some albumin is present, but the level is low and not usually symptomatic. 

A2: Moderately Increased Levels

 
In this case, protein content can vary between 30 to 300 mg/g or 3 to 30 mg/mmol. This indicates a detectable amount of elevated albumin, meaning greater kidney impact. The patients must discuss management options with their doctor to avoid additional damage to the kidneys. 

A3: Severely Increased Levels

 
In this phase, urine protein is more than 300 mg/g or 30 mg/mmol, indicating extreme kidney damage. An elevated albumin level raises the risk of developing kidney failure and heart disease. Urgent medical care is usually required to control health risks appropriately. 

Chronic Kidney Disease Symptoms 

 
Early CKD is frequently asymptomatic; symptoms typically appear in more advanced stages or due to associated conditions. Some of the symptoms of CKD are as follows: 

• Shortness of breath
• Loss of appetite 
• A frequent urge to urinate 
• Weakness, tiredness, and low energy levels 
• Swelling in ankles, feet, and hands 
• Puffiness in eyes 
• Itchy and dry skin 
• Bubbly or foamy urine 
• Sleeping and concentration issues 
• Vomiting or nausea 
• High blood pressure 
• Skin darkening 
• Cramps in the muscle 
• Numbness 

Chronic Kidney Disease Causes 

 
Chronic Kidney Disease (CKD) arises when kidneys are damaged and are no longer able to filter blood properly. The primary causes are high blood pressure and diabetes, which affect kidney function over time. Other causes include: 

• Glomerulonephritis: Injury to the filtering structures of the kidney
• Polycystic Kidney Disease: Genetic disease forming cysts in the kidneys 
• Membranous Nephropathy: An autoimmune disease attacking kidney membranes 
• Urinary Tract Obstructions: Enlarged prostate or tumours caused by kidney stones 
• Vesicoureteral Reflux: Urine flowing backwards to the kidneys 
• Nephrotic Syndrome: A group of signs that indicate renal damage 
• Recurrent Kidney Infections, Like pyelonephritis 
• Lupus and Other Autoimmune Disorders: Causes complications in the kidneys 

 
These diseases can cause chronic damage to the kidneys if not treated properly. So, one should get the proper treatment upon being diagnosed with CKD.  
 

Disclaimer: This article is intended for general informational and educational purposes only and should not be considered a substitute for professional medical advice, diagnosis, or treatment. Chronic Kidney Disease (CKD) is a complex condition, and its diagnosis and management depend on individual health factors, laboratory findings, and clinical evaluation. Readers should consult a qualified healthcare professional or nephrologist for personalized medical advice, accurate diagnosis, and appropriate treatment options.

Also Read:

→ What Food is Good for a Kidney Patient

→ Can Kidney Disease be Cured

→ What is Stage 1 Kidney Disease

→ How to Prevent Kidney Disease

→ What is Stage 4 Kidney Lupus