The stages of chronic kidney disease are determined by the glomerular filtration rate, which measures blood filtration by the kidneys, reports WebMD. In stage 1, the kidneys retain normal function, but by stage 5, they are in full failure.
The criteria for chronic kidney disease stages is based on the calculation of glomerular filtration rate. Stage 1 is diagnosed by a filtration rate of 90 or above, according to WebMD. The kidneys still function normally, but there is evidence of kidney damage in the body. The patient needs to monitor his blood pressure at this stage.
The second stage occurs when the glomerular filtration rate is anywhere from 60 to 89. At this stage, kidney function begins to deteriorate. Evidence besides the glomerular filtration rate is required to diagnose stages 1 and 2. A genetic history of kidney disease and a malformation of the kidneys are two possible criteria, as stated by The Renal Association.
A glomerular filtration rate between 30 and 59 classifies as stage 3 chronic kidney disease, notes The Renal Association. Patients should have regular appointments with a doctor to screen for complications. Kidney function decreases even further at this stage. The patient should be assessed for possible treatment options.
By stage 4, increasing damage to the kidneys results in drastically reduced function, The Renal Association explains. The glomerular filtration rate is between 15 and 29, and planning later treatment begins. Any glomerular filtration rate below 15 indicates stage 5 disease. Dialysis, kidney transplant and other treatment options are necessary at this time.