Table 1.

Classification of CKD by severity⁶

Stages of CKD	Description	GFR (mL/min/1.73m2)	Related terms
1	Kidney damage with normal or ↑ glomerular filtration rate	>90	Albuminuria, proteinuria, haematuria
2	Kidney damage with mild ↓ glomerular filtration rate	60-89	Albuminuria, proteinuria, haematuria
3	Moderate ↓ glomerular filtration rate	30-59	Chronic renal insufficiency, early renal insufficiency
4	Severe ↓ glomerular filtration rate	15-29	Chronic renal insufficiency, late renal insufficiency, pre-end stage renal disease
5	Kidney failure	<15 or dialysis	Renal failure, uraemia, end stage renal disease

The criteria for the definition of CKD are either kidney damage or glomerular filtration rate <60 mL/min for ≥3 months. Kidney damage is defined as pathological abnormalities or markers of damage, including abnormalities in blood or urine tests or imaging studies. CKD, chronic kidney disease; GFR, glomerular filtration rate