CKD is the result of irreversible loss of nephrons. The primary aetiologies of CKD in children are shown below. Click on the underlined headings for more information.
| Hypo / dysplasia | |
| - with identified uropathy | 43% |
| - without urinary tract malformation | 14% |
| Neurogenic bladder | 4% |
| Chronic glomerulonephritis | 4% |
| Focal glomerulosclerosis | 2% |
| Congenital nephrotic syndrome | 1% |
| Haemolytic uraemic syndrome | 4% |
| Polycystic kidney disease | 4% |
| Nephronophthisis | 4% |
| Alport's syndrome | 1% |
| Cystinosis | 2% |
| Other hereditary nephropathies | 4% |
| Miscellaneous | 13% |
However, the progression to renal failure follows a similar pathogenetic process irrespective of the primary disease.
The kidney tries to maintain function in the face of nephron loss by increasing the function of the remaining nephrons. This increase in individual nephron GFR is achieved by increasing the glomerular capillary pressure and this ultimately leads to further nephron loss and a down-hill spiral in renal function. Progression is perpetuated by all factors that contribute to the increase in single nephron GFR and glomerular pressure, particularly by hypertension and high dietary proteoin load.
The presence of this so-called "hyperfiltration injury" is heralded by the development of proteinuria.