CKD Stages: What Each Stage Means and What Comes Next

Doctors describe chronic kidney disease in five stages. The stages are built from two routine measurements that are usually reported together on the same lab visit:

• eGFR (estimated glomerular filtration rate) — a calculation, from a blood creatinine result, of how much blood your kidneys can filter per minute, adjusted for body size. A normal eGFR is 90 or above. See what eGFR means and how it is calculated.

• uACR (urine albumin-to-creatinine ratio) — how much albumin is in your urine. Albumin is a specific protein, and when kidneys are damaged it can leak into urine. A uACR of 30 mg/g (3 mg/mmol) or higher is called moderately increased. See how the uACR urine test works.

CKD is diagnosed when one of these is abnormal — an eGFR below 60 mL/min/1.73 m², or a uACR of 30 mg/g or higher — and the abnormality persists on repeat testing for at least three months. That three-month rule separates chronic disease from a short-term dip caused by dehydration, infection, or certain medicines.

The five stages then follow a simple ladder based on eGFR. On top of the stage, doctors also grade albuminuria (A1 to A3), because at the same eGFR, more albumin in the urine means a higher risk of progression:

• Stage 1 — eGFR 90 or above, with signs of kidney damage (such as albumin in the urine). Filtering is normal or high.

• Stage 2 — eGFR 60 to 89, with signs of kidney damage. Filtering is mildly reduced.

• Stage 3a — eGFR 45 to 59: a mild to moderate decrease.

• Stage 3b — eGFR 30 to 44: a moderate to severe decrease.

• Stage 4 — eGFR 15 to 29: a severe decrease.

• Stage 5 — eGFR below 15: kidney failure.

Stage 3 covers a wide range, which is why it is split into 3a and 3b. The split matters in practice: the risk of anemia, bone and mineral changes, and progression is noticeably higher from 3b onward, so monitoring usually becomes more frequent there.

Staging rests on lab tests, and it takes more than one set of results:

1. A blood test for creatinine, which is used to calculate eGFR. Some laboratories also use cystatin C to refine the estimate when creatinine alone is misleading.

2. A urine test for albumin and creatinine, reported together as the uACR.

3. Sometimes an ultrasound or other imaging to look at kidney size and structure, plus blood tests to identify causes such as diabetes.

The eGFR and uACR are repeated over time — typically at least three months apart — and the stable, persistent pattern is what sets your stage. One abnormal result, even a striking one, is not a stage on its own. If numbers sit near a boundary, clinicians generally use the result closest to normal after repeat testing, following the standard categories described in the eGFR categories used in staging.

You can track your own numbers. Ask for both the eGFR and the uACR at each visit, write them down, and pay attention to the trend rather than any single value. If eGFR falls below 30, or albuminuria reaches the higher grades, guidelines usually recommend that a kidney specialist (nephrologist) joins your regular care team.

The stage does not predict how you will feel on any given day, but it does shape what your care team watches for, how often you are checked, and which treatments matter most.

Stage 1

Your kidneys filter normally, but there is evidence of damage — most often albumin in the urine, or a structural finding on imaging. Most people feel no symptoms at all. Care focuses on the cause: blood pressure control, diabetes control, and medicines such as ACE inhibitors or ARBs when albuminuria is present. Those medicines do not suit everyone, so the choice is made with your clinician based on your overall assessment.

Stage 2

Filtering is mildly reduced, still a range that rarely causes symptoms. The plan looks much like stage 1: treat the underlying cause, review medicines for kidney safety, and recheck eGFR and uACR about once a year, or more often if results are changing.

Stage 3a

eGFR sits between 45 and 59. Most people still feel completely well. Monitoring usually tightens to every six to twelve months, adding checks such as blood counts or mineral levels when other results suggest they are starting to move.

Stage 3b

eGFR sits between 30 and 44. This is the range where complications such as anemia, bone and mineral changes, and higher cardiovascular risk are actively looked for. Visits are often every three to six months. Your team may adjust medicines — for example, starting treatment for anemia in CKD or planning phosphorus management if blood tests show changes — and a renal dietitian can help turn lab results into practical food choices.

Stage 4

eGFR is 15 to 29, a severe decrease. Symptoms such as fatigue, poor appetite, or trouble concentrating can appear at this point. Kidney specialists usually take a leading role, visits are often every one to three months, and planning for stage 5 begins early — learning about dialysis styles and, where relevant, transplant evaluation — so that later decisions are not made in a hurry.

Stage 5

eGFR is below 15: kidney failure. Waste and fluid build-up can cause nausea, itching, swelling, and breathlessness, although some people still feel relatively well for a time. Treatment planning becomes concrete: starting dialysis when the time is right, pursuing a transplant evaluation, or, after a full discussion with your team, choosing conservative care focused on comfort. Preparing dialysis access weeks or months ahead is typical, and you can read what to expect when starting dialysis to see what starting treatment involves.

Stages are defined by stable, chronic results, so several everyday situations can move the number without the underlying disease changing:

• Dehydration and acute illness: eGFR can dip during an infection, a stomach bug with vomiting, or hot-weather dehydration, then recover. This is one reason a single result never sets a stage.

• Body size and medicines: creatinine comes from muscle, so muscle mass, some supplements, and certain drugs shift the eGFR calculation without changing kidney health itself.

• Pregnancy and imaging contrast: eGFR is interpreted differently in pregnancy, and some contrast dyes need extra caution. Mention your CKD before any scan that uses contrast.

• Dialysis or transplant: once dialysis starts, the eGFR staging ladder no longer describes your situation — your team follows different markers. After a successful transplant, staging restarts based on the transplanted kidney's function.

What counts as real progression is a confirmed, sustained drop in eGFR category or a rise in albuminuria grade across repeat tests. That is why your team rechecks rather than reacting to one value — and why a sudden large swing deserves a phone call rather than a wait-and-see. Causes such as diabetes (see diabetes and kidney health) and interacting prescriptions (see medicines and CKD) are worth rechecking whenever numbers change faster than expected.

The same handful of measures protects kidney function at every stage, and they matter most before symptoms ever appear:

• Blood pressure: keeping it at the target your clinician sets is the single most protective habit. Home readings make this measurable. See blood pressure and kidney health.

• Diabetes control, when present: glucose management slows kidney damage directly.

• Kidney-safe medicine review: avoid regular NSAIDs such as ibuprofen and naproxen, and remind every prescriber — including dentists — about your CKD before new prescriptions or contrast scans.

• Keep taking prescribed kidney medicines: ACE inhibitors, ARBs, and SGLT2 inhibitors are often used to protect the kidneys when appropriate. They are not right for everyone, so choices and doses belong to your team — do not stop or change any prescribed medicine on your own.

• Practical diet help: a renal dietitian can tailor protein, salt, potassium, and phosphorus advice to your labs. Broad restrictions do not apply to every patient.

• Sick-day awareness: if you cannot eat or drink normally, ask your team which medicines to pause. Significant dehydration is hard on kidneys.

Most staging questions — a new number you do not understand, a test scheduled for next month — can wait for a routine visit. Some situations need a call the same day, and a few need emergency care.

Contact your team the same day for:

• A sudden, large drop in eGFR on a new lab result, or a big unexplained rise in uACR

• New or rapidly worsening swelling in the legs or face, or fast weight gain from fluid

• Vomiting or diarrhea lasting more than a day, since dehydration can push kidney numbers down

• New or worsening nausea, itching, or unusual drowsiness if you are at stage 4 or 5

Bring your questions to routine visits — that is exactly what they are for:

• Which stage am I in, and what were my exact eGFR and uACR numbers?

• How often should we recheck, and what trend would worry you?

• Which of my medicines protect the kidneys, and which could harm them?

• At what point should we start talking about dialysis or transplant planning?