Conclusion
The stage of chronic kidney disease is determined by evaluating how well the kidneys are working. This is usually measured using glomerular filtration rate (GFR) [3], which shows how much blood your kidneys can filter in one minute. It is measured by checking levels of creatinine in the blood. Creatinine is waste from muscle activity filtered by the kidneys. The amount found in the blood usually increases with a decline in kidney function.
Not everyone with kidney disease eventually develops kidney failure. There is no cure for the disease, but early detection and treatment can stop or slow its progression. Symptoms of kidney failure are virtually nonexistent in the early stages, which is why you should perform regular checks, especially if you have predisposing health conditions.
References:
[1] https://www.medicinenet.com/kidney_failure/article.htm
[2] http://www.davita.com/kidney-disease/vocabulary/chronic-kidney-disease/e/5398
[3] https://www.healthline.com/health/glomerular-filtration-rate
[4] https://www.davita.com/education/kidney-disease/stages/stage-1-of-chronic-kidney-disease
[5] https://www.healthline.com/health/ckd-stages#stage-2
[6] https://www.davita.com/education/kidney-disease/stages/stage-3-of-chronic-kidney-disease
[7] https://nephcure.org/livingwithkidneydisease/what-is-kidney-disease-2/
[8] https://www.cdc.gov/kidneydisease/basics.html
[9] https://www.davita.com/education/kidney-disease/stages/stage-5-of-chronic-kidney-disease