The stages of CKD (Chronic Kidney Disease) are mainly based on measured or estimated GFR (Glomerular Filtration Rate). There are five stages but kidney function is normal in Stage 1, and minimally reduced in Stage 2.
The KDOQI stages of kidney disease are:
* All GFR values are normalized to an average surface area (size) of 1.73m2
- p suffix: the addition of p to a stage (e.g. 3Ap, 4p) means that there is significant proteinuria (more info)
- T - the addition of T to a stage (e.g. 3AT) indicates that the patient has a renal transplant.
- D - the addition of D to stage 5 CKD (e.g. 5D) indicates that the patient is on dialysis
Definition of chronic: Labelling someone as having CKD requires two samples at least 90 days apart. Historical values can be used.
Stage 2 kidney disease may be overdiagnosed by eGFR, because equations used to predict GFR (rather than real measurements) may give falsely low results in people with near-normal function.
Information about stages of CKD for patients
The stages of CKD shown in the table above are a useful aid to planning. A number of websites have further information. See general links from the foot of the CKD eGuide home page.
It is important to remember that where you are placed into CKD stage 3 or higher, it usually depends on an estimate of kidney function. These estimates are not completely precise, but usually they are reliable enough to provide useful information. More info about tests in kidney disease (EdREN). More technical info about eGFR
My stage keeps changing: It is normal for measurements of creatinine and therefore GFR to change a bit from one measurement to the next. In some patients these changes may seem large, and enough to move you from one stage to another and then back again. As long as things aren't getting progressively worse, it is the average that is important.