Chronic kidney disease (CKD} happens when 85-90% of your kidney gets damaged and becomes functionally impaired.
Doctors have staged the progression of chronic kidney disease (CKD) from stage 1 to stage 5 in the increasing order of its severity. These stages are based on your glomerular filtration rate (GFR).
GFR is a test that is used to check the functioning of your kidneys. Its results are in the form of mL/min, which is the amount of blood that passes through each filtering unit (glomeruli) of the kidney in a minute.
The GFR is calculated from your serum creatinine levels, your body size, age, sex, and ethnicity.
Table 1. Stages of CKD with corresponding GFR and kidney function
Stages of CKD
GFR in mL/min
Status of kidney function
Normal kidney function
A mild decline in kidney function
A moderate decline in kidney function
A severe decline in kidney function