Kidney disease ascends in severity from Stage 1 to Stage 5, according to The Renal Association. Kidney function is typically normal in Stage 1, while reducing mildly in function by Stage 2.
Persons in Stages 3A and 3B experience a moderate decrease in function, while those at Stage 4 suffer from severely reduced kidney function. Once a patient has reached Stage 5, dialysis and kidney transplant may be the only treatment options for the very severe or endstage kidney failure.
The stage of kidney disease is determined by glomerular filtration rate; patients may progress through the stages very slowly or very quickly depending on diagnosis and treatment.