CKD Stages Explained: A Complete Guide to Chronic Kidney Disease

Chronic Kidney Disease (CKD) is a condition where the kidneys gradually lose their ability to filter waste and excess fluid from the blood. It affects roughly 1 in 7 adults in the United States, or about 37 million people. Because early stages often present no symptoms, many people are unaware they have the condition.

We call CKD "chronic" because the damage occurs slowly over months or years. Diabetes and high blood pressure are the two primary drivers of kidney failure, accounting for approximately 44% and 29% of cases, respectively.

How CKD Stages Work

CKD is classified into 5 stages based on your eGFR (estimated glomerular filtration rate). This number represents how well your kidneys are filtering blood; the higher your eGFR, the better your kidney function.

Stage 1: Normal or High Function (eGFR ≥ 90)

At Stage 1, kidneys are still functioning normally or near-normally, but there is evidence of kidney damage, such as protein in the urine (albuminuria), abnormal kidney structure, or a genetic kidney condition.

Symptoms: Usually none. Most people feel completely normal.

What to do: Identify and treat the underlying cause, control your blood pressure, and schedule annual kidney function tests. This is the most impactful stage for intervention; catching CKD early often allows you to prevent further progression.

Stage 2: Mildly Decreased (eGFR 60-89)

A mild decrease in kidney function. This is very common, especially in people over 60, and may not indicate a problem on its own.

Symptoms: Usually none. Kidneys are still working well enough that waste products don't build up.

What to do: Monitor eGFR every 6-12 months. Control blood pressure (target <130/80). If you have diabetes, optimize blood sugar. Maintain a healthy lifestyle.

Stage 3: Mild to Moderate Decrease (eGFR 30-59)

Stage 3 is subdivided into 3a (eGFR 45-59) and 3b (eGFR 30-44). This is where CKD starts to require more active management.

Symptoms: Many people still feel fine, but some may notice fatigue, swelling in hands/feet, changes in urination, or back pain. Lab tests may show anemia, bone mineral imbalances, or electrolyte changes.

What to do: See a nephrologist. Ask about ACE inhibitors/ARBs (kidney-protective medications). Follow a moderate-protein, low-sodium diet. Avoid NSAIDs. Get labs checked every 3-6 months. This is the critical stage where lifestyle changes make the biggest difference.

Stage 4: Severely Decreased (eGFR 15-29)

Severe decrease in kidney function. Symptoms are common and complications need active management.

Symptoms: Fatigue, nausea, loss of appetite, swelling, changes in urination, itchy skin, muscle cramps, shortness of breath.

What to do: Work closely with your nephrologist. Discuss dialysis preparation and transplant evaluation. Follow strict dietary restrictions (potassium, phosphorus, sodium, fluid). Get labs checked monthly. Consider vascular access surgery if hemodialysis is planned.

Stage 5: Kidney Failure (eGFR < 15)

Kidneys can no longer adequately sustain life. Most patients at this stage need dialysis or a kidney transplant.

Symptoms: Severe fatigue, nausea, vomiting, swelling, shortness of breath, confusion, itching. Without treatment, toxins build to dangerous levels.

What to do: Begin or continue dialysis. Get on the transplant waiting list. Follow strict dietary and fluid management. Take all prescribed medications. Connect with support groups.

How to Slow CKD Progression

The most important thing to understand about CKD: it's not necessarily a one-way street. With the right steps, you can significantly slow or even halt progression, especially in stages 1-3.

1. Blood pressure control — Target <130/80 mmHg. This is the single most impactful intervention.
2. Blood sugar management — For diabetics, HbA1c <7% is the general target.
3. SGLT2 inhibitors — New medications (like Jardiance, Farxiga) have shown remarkable kidney-protective benefits, even in non-diabetics.
4. ACE inhibitors/ARBs — These blood pressure medications reduce pressure inside the kidneys.
5. Diet — Moderate protein, low sodium, kidney-appropriate potassium and phosphorus.
6. Avoid nephrotoxins — NSAIDs, certain supplements, and some antibiotics can accelerate damage.
7. Don't smoke — Smoking accelerates kidney function decline.