Stages of Chronic Glomerulonephritis: Understanding Progression and Kidney Function Levels

Chronic glomerulonephritis is a progressive kidney disorder characterized by long-term inflammation of the glomeruli—the tiny filtering units in the kidneys. The disease is typically classified into stages based on the level of kidney function, primarily measured by the estimated glomerular filtration rate (eGFR), which correlates closely with endogenous creatinine clearance. As the condition advances through its stages, renal function declines, leading to more severe complications. Early detection and proper management tailored to each stage are essential for slowing disease progression and improving patient outcomes.

How Chronic Glomerulonephritis Is Staged

The staging of chronic glomerulonephritis reflects the gradual loss of kidney function over time. Medical professionals use these stages to guide treatment plans, monitor disease progression, and help patients make informed lifestyle and therapeutic decisions. Each stage corresponds to a specific range of creatinine clearance values, indicating how well the kidneys are filtering waste from the blood.

Stage I: Mild Kidney Impairment

In the earliest phase, kidney damage may be present but overall function remains normal or near-normal. This stage is defined by an endogenous creatinine clearance rate of 90 mL/min or higher. Patients often experience no noticeable symptoms, and the condition may only be detected through routine blood or urine tests. At this point, early intervention—such as controlling blood pressure, managing proteinuria, and adopting a kidney-friendly diet—can significantly delay further deterioration.

Stage II: Mild to Moderate Decline

As kidney function begins to decline, patients enter Stage II, where creatinine clearance ranges between 60 and 89 mL/min. Although symptoms may still be minimal or absent, subtle signs like mild fatigue or slight changes in urination patterns might appear. It's crucial during this phase to conduct regular monitoring and implement protective strategies, including tighter control of underlying conditions such as diabetes or hypertension.

Stage III: Moderate to Severe Loss of Function

Stage III marks a significant turning point, with creatinine clearance dropping to 30–59 mL/min. This stage is often subdivided into IIIa (45–59 mL/min) and IIIb (30–44 mL/min) to better reflect the degree of impairment. Patients may begin experiencing symptoms such as swelling in the legs, fatigue, changes in urine output, or anemia. Nephrologist involvement becomes increasingly important, and treatment focuses on slowing progression, managing complications, and preparing for potential future interventions.

Stage IV: Severe Kidney Damage

At this critical stage, kidney function is severely compromised, with creatinine clearance falling to 15–29 mL/min. Symptoms become more pronounced, including nausea, shortness of breath, difficulty concentrating, and persistent edema. Patients are typically referred to a kidney specialist to discuss advanced care options, including dialysis planning and evaluation for kidney transplantation. Lifestyle modifications, medication adjustments, and nutritional counseling play a vital role in maintaining quality of life.

Stage V: End-Stage Renal Disease (ESRD)

When creatinine clearance drops below 15 mL/min, the patient has reached Stage V—also known as end-stage renal disease. At this point, the kidneys can no longer sustain basic bodily functions without external support. Dialysis or a kidney transplant becomes necessary for survival. Comprehensive care involving a multidisciplinary team is essential to manage complications such as fluid overload, electrolyte imbalances, and cardiovascular risks.

Conclusion: Importance of Early Detection and Management

Understanding the stages of chronic glomerulonephritis empowers patients and healthcare providers to take timely, effective action. Regular screening, especially for individuals with risk factors like autoimmune diseases, hypertension, or a family history of kidney disorders, is key to early diagnosis. With appropriate medical guidance and proactive lifestyle choices, it's possible to slow disease progression and maintain a better quality of life throughout the journey.