Chronic Kidney Disease

Topic written or edited by:

Samuel S. Blumenthal, MD
Barbara A. Bresnahan, MD
Jack G. Kleinman, MD
Walter F. Piering, MD, FACP

Stages of Chronic Kidney Disease (CKD)
eGFR (Glomerular Filtration Rate)



GFR Level

Normal kidney function

Healthy kidneys

90 mL/min or more

Stage 1

Kidney damage with normal or high GRF

90 mL/min or more

Stage 2

Kidney damage and mild decrease in GFR

60 to 89 mL/min

Stage 3

Moderate decrease in GFR

30 to 59 mL/min

Stage 4

Severe decrease in GFR

15 to 29 mL/min

Stage 5

Kidney failure

Less than 15 mL/min or on dialysis


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  Stages of Chronic Kidney Disease

Your Glomerular Filtration Rate (GFR) is the best indicator of how well your kidneys are working. In 2002, the National Kidney Foundation published treatment guidelines that identified five stages of Chronic Kidney Disease (CKD) based on declining GFR measurements. The guidelines recommend different actions based on the stage of kidney disease.

  • Increased risk of CKD. A GFR of 90 or above is considered normal. Even with a normal GFR, you may be at increased risk for developing CKD if you have diabetes, high blood pressure, or a family history of kidney disease. The risk increases with age: People over 65 are more than twice as likely to develop CKD as people between the ages of 45 and 65. African Americans also have a higher risk of developing CKD.
  • Stage 1: Kidney damage with normal GFR (90 or above). Kidney damage may be detected before the GFR begins to decline. In this first stage of kidney disease, the goals of treatment are to slow the progression of CKD and reduce the risk of heart and blood vessel disease.
  • Stage 2: Kidney damage with mild decrease in GFR (60 to 89). When kidney function starts to decline, your health care provider will estimate the progression of your CKD and continue treatment to reduce the risk of other health problems.
  • Stage 3: Moderate decrease in GFR (30 to 59). When CKD has advanced to this stage, anemia and bone problems become more common. Work with your health care provider to prevent or treat these complications.
  • Stage 4: Severe reduction in GFR (15 to 29). Continue following the treatment for complications of CKD and learn as much as you can about the treatments for kidney failure. Each treatment requires preparation. If you choose hemodialysis, you will need to have a procedure to make a vein in your arm larger and stronger for repeated needle insertions. For peritoneal dialysis, you will need to have a catheter placed in your abdomen. Or you may want to ask family or friends to consider donating a kidney for transplantation.
  • Stage 5: Kidney failure (GFR less than 15). When the kidneys do not work well enough to maintain life, you will need dialysis or a kidney transplant.
  Early Chronic Kidney Disease (Stages 1 to 2)
  • Physical symptoms: Usually few or no physical symptoms that you can feel (other than those you may experience if you have a lot of protein in your urine).
  • Blood work: Blood work results will show abnormalities - mainly a slightly elevated serum creatinine.
  • Urinalysis: Urine will show abnormalities. Urine can be checked by dipstick in the doctor's office (as an initial check) and followed up with a more complete urinalysis. The main urine abnormality that will suggest a kidney disease is the presence of protein and/or blood. Either will usually trigger further investigation. Importantly, blood and/or protein in the urine does not say anything about actual kidney function.
  • Treatment: Treatment may involve some mild dietary changes (a lower sodium diet is often recommended) and a blood pressure medication may be prescribed (usually of the ACE inhibitor class or the angiotensin II receptor blocker class) even if blood pressure is not really elevated much.
  • Blood pressure: Some people start having high blood pressure even in early chronic kidney disease.
  • Anemia: Anemia may rarely occur at this stage. In this case, it is most often caused by having a lot of protein in the urine rather than actual chronic kidney disease.
  Advanced Chronic Kidney Disease (Stages 3 to 4)
  • Physical symptoms: You may still feel completely normal at this stage, or you may begin to experience one or more of the following symptoms:
    • Tiredness or fatigue
    • Puffiness or swelling (obvious in the hands or feet and ankles, but the puffiness will often first be seen around the eyes).
    • Back pain. Usually felt as a dull ache anywhere in the mid-to-lower portion of the back, on one side or the other - this is sometimes referred to as flank pain, or loin pain.
    • Changes in appetite or eating pattern. Foods may start tasting "funny".
  • Urine: Changes in urination (amount, color, frequency). Urine may in fact look exceptionally clear at this point. This is because little is actually being filtered by your kidneys. Some patients that previously had blood or protein in the urine may see these findings improve.
  • Blood pressure: High blood pressure (also referred to as hypertension) is common.
  • Digestion: Poor digestion (varying degrees of gastroparesis, which means that digestion is slowed).
  • Treatment
    • Diet: Dietary changes may be ordered (Kidney diet: low potassium, low phosphorus, low sodium, and higher calorie). Occasionally a lower protein diet may be advised.
  • Medication
  • High blood pressure medications: It is common to need more than one medication at this stage (often 3 or more).
  • Other drugs/supplements may be prescribed if needed. Including vitamin D and kidney vitamins (not a regular multi-vitamin, as these contain too much vitamin A for the typical advanced kidney disease patient).
  • High Phosphorus levels: You may be asked to begin taking a calcium supplement with meals as a phosphorus binder. These medications help keep phosphorus levels in the normal range which helps protect your blood vessels from harmful build up.
  End-stage renal disease (or late chronic kidney disease) (ESRD)

The terms end-stage renal failure and end-stage renal disease are used interchangeably, and the abbreviation ESRD is commonly used. Typically, patients will have kidney function in the area of 5-10% or so. These are the common symptoms you may experience at this stage (and some people may start experiencing some of these earlier):

  • anemia (may begin earlier than this)
  • easy bleeding and bruising
  • headache
  • fatigue and drowsy feeling (more than normal or usual for you)
  • weakness
  • mental symptoms such as lowered mental alertness, trouble concentrating, confusion, seizures
  • nausea, vomiting, and generally less desire to eat
  • thirst
  • muscle cramps, muscle twitching
  • increased night-time urination
  • numb sensation in the extremities
  • diarrhea
  • itchy skin, itchy eyes
  • skin color changes (grayish complexion, sometimes yellowish-brownish tone)
  • swelling and puffiness (more than you had while in advanced kidney disease, and most likely in the feet and/or ankles)
  • difficulty breathing (due to fluid in the lungs, anemia)
  • high blood pressure
  • decreased sexual interest
  • changes in menstrual cycle (and difficulty getting pregnant)
  • decreased urine output (however, you should be aware that some people with ESRD will continue to get rid of water as urine, but not wastes - therefore, the urine may be very clear and normal-looking, and some may have increased urine output rather than decreased).
  • poor digestion (varying degrees of gastroparesis)

The exact time that dialysis starts varies slightly depending on multiple factors. Consult your nephrologist.

  • Dialysis
  • Kidney transplant
  What happens when you approach ESRD?

It is at this stage that you are on the threshold of needing renal replacement therapy (any form of dialysis or a kidney transplant). When this actually happens will depend on your symptoms and lab results. It will occur as you get close to 10% kidney function (by which time the special kidney diet and medications will no longer be enough to keep you healthy). You will be considered to be approaching ESRD when you are under 20% kidney function (as measured by Glomerular Filtration Rate), and more actively as you approach 10% kidney function.

  Sequence of events when you approach ESRD

Some localities, such as many major urban centers, may have a very complete "system" that patients come under or have access to as they approach or reach ESRD. Other areas might not. The sequence of events given below is typical, but it's possible that some of the items listed might not be available where you live, or your nephrologist may vary it slightly. It is provided as a guide so that you will know what to expect and what to discuss with your nephrologist.

20-30% kidney function

Refer for Renal Replacement Therapy classes, also referred to as pre-dialysis classes. This is where patients are introduced to the concept of the kidney diet and have the renal replacement options explained to them, i.e. hemodialysis, peritoneal dialysis, and kidney transplantation. This allows patients to make an informed choice of treatment method when the time comes. In some areas, handouts may be used in place of actual classes. Around this time, you will probably also be told to start taking calcium with meals as a phosphorus binder, if you haven't already (don't do this on your own).

15-20% kidney function (or thereabouts)

Sometime during this timeframe your nephrologist will want you to choose a dialysis method so that the dialysis access to your body can be arranged. This is also the time when patients can be evaluated for kidney transplantation. Your nephrologist may also ask if you have any potential kidney donors.

  Arteriovenous fistula (for hemodialysis)

Called AV fistula for short, or just fistula. This is considered the best way of performing hemodialysis. A fistula is really just a vein near the surface of your lower or upper arm, that has been connected to an artery by a vascular surgeon. It requires surgery in your arm (usually in a day surgery setting). Surgery should usually be scheduled a good 6 months before the date dialysis is expected to be needed because a fistula needs time to develop. It's not too early to have it done a year before expected dialysis. That way, if you have to start dialysis earlier than expected (as often happens), your fistula will be ready for use by the time you need it. Preparing in this way helps you start dialysis without requiring a catheter inserted in your chest. Importantly, it doesn't hurt to have that fistula ready and waiting if it turns out you don't need to start dialysis right away.

  Graft or shunt (for hemodialysis)

This is similar to an AV fistula, but whereas the fistula uses a natural vein in your arm, a graft is an artificial piece of tubing that is implanted in your arm to serve the same purpose. People who choose hemodialysis but who don't have suitable veins for fistula surgery may need to have a graft instead of a fistula. The word shunt is often used, but it is an obsolete term in this context. Some health professionals in dialysis may even refer to a fistula as a shunt.

  Abdominal catheter (for peritoneal dialysis)

If you choose peritoneal dialysis (PD), a surgeon will have to insert a plastic tube in your abdomen, through which you will perform your dialysate fluid exchanges. This can be placed closer to the need for dialysis (about 1 month before the need).

  Potential kidney donors (for pre-emptive transplant)

Some people may want to consider having a kidney transplant when they reach ESRD rather than having to go on dialysis. This is called a pre-emptive transplant. Obviously, this requires having a suitable and pre-qualified donor lined up. As both the patient's pre-evaluation as a potential kidney transplant recipient, and the donor's pre-evaluation as a potential kidney donor can take some time (weeks or months in some cases), this is best performed well-ahead of time (i.e. the year leading up to anticipated ESRD). There can be many medical or psychological/social reasons that a potential kidney donor is rejected, and, unfortunately, it's not unheard of for a qualified kidney donor to back out of it very late in the process. Or sometimes, an illness will make it impossible to get the transplant at the time it's needed. For that reason, many nephrologists will suggest that you also choose a method of dialysis just in case it's needed (given the lead time that is required for the access surgery). Therefore, even a patient with a donor all pre-qualified for an expected pre-emptive transplant might still have fistula surgery performed, or a PD catheter inserted.

Kidney transplant waiting list

If you do not plan to have a pre-emptive kidney transplant, it's still a good idea to go through your evaluation as a potential kidney transplant recipient before you start dialysis. That way, you will be on the waiting list and able to receive a kidney if one should come along soon after you start dialysis. Otherwise, you could miss out if your evaluation is only started once you are on dialysis.

Some important information about getting listed:

Getting on the waiting list does not happen automatically. Make sure your nephrologist knows you want a transplant, and that however it happens, you do actually get referred to a kidney transplant center. Once this happens, you will need to go through a potential kidney transplant recipient evaluation, which usually includes a complete medical evaluation, medical tests (such as various heart tests), a psychological and/or social worker evaluation, interviews with a transplant nephrologist and a transplant surgeon. This evaluation can easily take a number of months. It usually can be completed before you actually reach the point of needing dialysis.

In Canada, you can be evaluated while you are pre-dialysis, but the exact rules which govern may vary from Province to Province, and from region to region within each province. Using the Province of Ontario as an example, no matter when you complete the evaluation, before or after having started dialysis, your time on the waiting list begins the exact date that you start dialysis, not before (it is retroactive if you completed the evaluation after having started dialysis). If you have a potential live donor, you will be put on hold from the waiting list while that person is being evaluated. This is done because a kidney from a live donor is considered to be superior to one from the waiting list. The reasoning behind starting everyone's time on the waiting list as of the date of first dialysis is that evidence has shown that the longer a person is on dialysis, the more overall health declines. Therefore, it is believed to be more fair to everyone that time on the list begins on the date of first dialysis. Some people may have completed their evaluation before dialysis, some after. Some may have been on hold one or more times because of other illnesses, etc., but nobody is penalized for having had delays in their potential recipient evaluation or for having had other illnesses during the course of dialysis.

In the United States, you can usually be evaluated as a potential kidney transplant recipient within the 2-3 year period before you would be expected to start dialysis. If you have done so, credit for waiting time on the waiting list begins when you have reached 20% kidney function (more precisely, a GFR of less than 20, as per a rule change implemented by UNOS in 1998). Since dialysis is typically started when GFR is about 10%, it is therefore possible to obtain a cadaveric kidney transplant before having actually started dialysis.

15 to 10% kidney function (more or less). It will vary based on a patient's symptoms, but this is the timeframe when dialysis is started. A person who is diabetic will often be started at 15% kidney function, while most IgAN patients would start at about 10%. It's common practice these days to start dialysis in a planned manner, rather than waiting until it becomes an emergency situation (thankfully!). Most people will either start dialysis or have the pre-emptive kidney transplant done when or slightly before they reach 10% kidney function. Some people may reach 10% without experiencing any major symptoms, but, generally, dialysis will be started at this point, if not slightly before, in a planned fashion, even if the patient doesn't feel any significant symptoms. Since there is still about 10% kidney function at this point, it may be possible to continue quite some time without dialysis, but starting dialysis early increases chances of an easier transition, and it allows time to initiate dialysis in a way that minimizes stress on the body.

Contrary to popular misconception, there is no advantage to being able to delay dialysis even if no symptoms of renal failure are felt once kidney function (glomerular filtration rate) reaches about 10%, and there may in fact be significant disadvantages for the patient in terms of mortality and morbidity.