CKDstadier

CKDstadier, or the stages of chronic kidney disease, is a framework used to describe how well the kidneys function and how much damage is present. Stages are typically defined by the estimated glomerular filtration rate (eGFR) and by markers of kidney damage such as albuminuria. The KDIGO system commonly summarizes this in five stages, with an emphasis on eGFR categories and the presence of kidney damage.

Stage 1: eGFR ≥90 ml/min/1.73 m2 with evidence of kidney damage (for example, albuminuria, structural abnormalities). Stage 2: eGFR 60–89 with kidney damage. Stage 3 is split into Stage 3a: eGFR 45–59 and Stage 3b: eGFR 30–44. Stage 4: eGFR 15–29. Stage 5: eGFR <15 or dialysis/kidney replacement therapy is underway.

Albuminuria is categorized separately to indicate risk and progression. A1 corresponds to less than 30 mg/g creatinine, A2 to 30–300 mg/g, and A3 to more than 300 mg/g. Higher levels of albuminuria indicate greater risk of progression and complications, even if eGFR is not severely reduced.

Management focuses on slowing progression and addressing complications. Key measures include blood pressure control, often with targets around 130/80 mmHg or lower in the presence of albuminuria; use of renin–angiotensin system inhibitors (ACE inhibitors or ARBs) for proteinuria; glycemic control in diabetes; consideration of SGLT2 inhibitors where appropriate; lipid management; and lifestyle modification. Regular monitoring for anemia, bone-mineral disorders, electrolyte disturbances, and acid-base balance is recommended. Nephrology referral is advised for stages 4–5 or rapid progression, and for planning kidney replacement therapy when needed.