Table 2.

Definition and staging of CKD

CKD is defined as either of the following present for >3 months
1) Markers of kidney damage (one or more)
	Albuminuria, urine sediment abnormalities, electrolyte, or other abnormalities attributable to tubular disorders, abnormalities detected by histology, structural abnormalities detected by imaging, history of kidney transplantation
2) Decreased GFR; GFR <60 mL/min/1.73 m2 (GFR categories G3a–G5)
GFR category	GFR (mL/min/1.73 m2)		Albuminuria category	AER (mg/day)
G1	>90	Normal or high	A1	<30	Normal to mildly increased
G2	60–89	Mildly decreased	A2	30–300	Moderately increased
G3a	45–59	Mildly to moderately decreased	A3	>300	Severely increased
G3b	30–44	Moderately to severely decreased
G4	15–29	Severely decreased
G5	<15	Kidney failure

GFR glomerular filtration rate, AER albumin excretion rate