Kidney disease describes a variety of conditions and disorders that affect the kidneys.  Most kidney disease attack the filtering units of the kidneys—the nephrons—and damage their ability to eliminate wastes and excess fluids. Kidney disease can range from mild to severe and in some cases, lead to kidney failure (sometimes referred to as end-stage kidney disease).

Chronic kidney disease(CKD) is the presence of kidney damage, or a decreased level of kidney function, for a period of three months or more. Kidney disease can range from mild to severe and in some cases, lead to kidney failure (sometimes referred to as end-stage kidney disease, or ESKD). Kidney disease often starts slowly and develops without symptoms over a number of years, so CKD may not be detected until it has progressed to the point where your kidney function is quite low. Fortunately, most people do not progress to end-stage kidney disease, especially if they are diagnosed early and are able to take steps to preserve their remaining kidney function.

End-stage kidney disease means the end of your kidney function: your kidneys no longer adequately filter your blood. If your kidneys fail, there are a number of different treatment options including different forms of dialysis, transplantation or non-dialysis supportive care. 

Sometimes kidney failure occurs rapidly and this is called acute kidney injury. This may be a result of infection, diseases that specifically attack the kidney filters, or other causes. For acute kidney injury, dialysis treatment may be urgently needed for a period of time, but kidney function often recovers.

Your glomerular filtration rate (GFR) shows the amount of kidney function you have remaining. Your GFR, your symptoms, your overall health and other factors (such as the amount of albumin in your urine) help your health care team manage your health, monitor your kidney function and determine the type of treatment that’s best for you.

 NORMALMILDMODERATESEVEREKIDNEY FAILURE
Amount of Kidney function> 60%*45%-59%30%-44%15%-29%< 15%
SymptomsNo symptoms observedNo symptoms observedEarly symptoms may occur and could include tiredness, poor appetite, and itchingTiredness, poor appetite and itching may get worseSymptoms may include severe fatigue, nausea, difficulty breathing and itchiness
Treatment OptionsIdentify cause and try to reverse it
 
Monitor albumin and GFR
Monitor albumin and GFR, blood pressure, general health and well-being
 
Try to stop or slow down the worsening of kidney function
 
Monitor albumin and GFR, and continue to try to stop or slow the worsening of kidney function
 
Learn more about CKD and treatment options
Monitor albumin and GFR, and continue to try to stop or slow the worsening of kidney function
 
Discuss and plan for treatment choice: dialysis access, assessment for transplant, or information about non-dialysis supportive care
Monitor albumin and GFR and continue to try to stop or slow the worsening of kidney function
 
Continue with non-dialysis supportive care, plan for transplant or start dialysis (depending on symptoms) **

* Normal unless there is an underlying issue, kidney damage or albumin in the urine.
** The timing of starting dialysis treatment depends on a large number of factors. This should be discussed with your doctors and health care team.

Reference: https://kidney.ca/Kidney-Health/Newly-Diagnosed/What-is-Kidney-Disease