Understanding Chronic Kidney Disease: Causes, Stages, and Treatment Options
Chronic kidney failure is an outdated term that has been replaced by the more accurate and widely accepted medical diagnosis of chronic kidney disease (CKD). This condition refers to long-term damage to the kidneys that impairs their ability to function properly. It is diagnosed when a person shows abnormalities in urine, blood, or kidney tissue structure, or when the glomerular filtration rate (GFR) remains below 60 ml/min/1.73m² for three months or longer. CKD can develop slowly over time and often goes unnoticed until significant damage has occurred.
Primary vs. Secondary Causes of Chronic Kidney Disease
Chronic kidney disease can stem from a variety of underlying causes, which are generally classified into two main categories: primary and secondary.
Primary Causes
These originate directly within the kidneys themselves. Conditions such as chronic glomerulonephritis, polycystic kidney disease, or recurrent kidney infections fall under this category. In these cases, the disease process begins in the renal tissues without being triggered by another systemic illness.
Secondary Causes
These result from health disorders affecting other parts of the body that indirectly harm the kidneys. Common examples include diabetes mellitus—the leading cause of CKD—and hypertension (high blood pressure). Other contributing factors may include autoimmune diseases like lupus, prolonged use of nephrotoxic medications, or cardiovascular disease. Managing these underlying conditions is crucial in slowing the progression of kidney damage.
Stages of Chronic Kidney Disease Based on GFR
One of the key tools used to assess the severity of CKD is the glomerular filtration rate (GFR), which measures how well the kidneys filter waste from the blood. Based on GFR values, chronic kidney disease is divided into five progressive stages:
- Stage 1: GFR > 90 ml/min/1.73m² – Kidney damage is present, but kidney function is normal or near-normal.
- Stage 2: GFR 60–89 ml/min/1.73m² – Mild reduction in kidney function with evidence of structural or functional damage.
- Stage 3: GFR 30–59 ml/min/1.73m² – Moderate to moderately severe loss of kidney function; patients may begin experiencing symptoms such as fatigue, swelling, or changes in urination.
- Stage 4: GFR 15–29 ml/min/1.73m² – Severe decline in kidney function; at this point, preparation for renal replacement therapy typically begins.
- Stage 5: GFR < 15 ml/min/1.73m² – Also known as end-stage renal disease (ESRD), where the kidneys have lost nearly all ability to filter toxins and excess fluid from the body.
Treatment and Management at Advanced Stages
When chronic kidney disease reaches Stage 5, also historically referred to as end-stage chronic kidney failure, the kidneys are no longer able to sustain basic bodily functions. At this critical stage, patients require life-sustaining interventions such as dialysis—either hemodialysis or peritoneal dialysis—to artificially remove waste products and regulate electrolyte balance.
In suitable candidates, kidney transplantation offers the best long-term outcome, providing improved quality of life and greater survival rates compared to ongoing dialysis treatment. However, access to transplant depends on donor availability, patient health status, and comprehensive medical evaluation.
Early detection through routine blood and urine screening, effective management of comorbid conditions like diabetes and hypertension, and lifestyle modifications—including a balanced diet, regular exercise, and avoidance of smoking and excessive medication use—are essential strategies for preventing or delaying the progression of chronic kidney disease.