Chronic kidney disease (CKD) is defined by the progressive loss of kidney function over time, characterized by kidney damage or an estimated glomerular filtration rate (eGFR) of less than 60 mL/min/1.73 m² for three months or more. CKD can result from a variety of underlying conditions, such as diabetes mellitus, hypertension, or glomerulonephritis. The disease involves a gradual reduction in the kidney's ability to filter waste, regulate electrolytes, and maintain fluid balance, eventually leading to end-stage renal disease (ESRD), where renal replacement therapy (dialysis or transplantation) is required. Early recognition and management of CKD are crucial to slow disease progression and prevent complications.
The 2012 Kidney Disease: Improving Global Outcomes (KDIGO) classification categorizes CKD into six stages based on eGFR (G1 to G5) and three levels of proteinuria (A1, A2, A3) based on albumin excretion. CKD stages range from mild (G1, G2) to severe (G5), which represents end-stage renal disease. Staging helps in predicting disease progression and guiding treatment strategies, with higher stages indicating a greater risk of complications and more advanced kidney damage.
