CKD Stages 1-5: What Each Stage Means for Your Health and Diet

TL;DR: CKD stages range from 1 (mild damage with normal function) to 5 (kidney failure requiring dialysis or transplant). Each stage has different symptoms, treatment priorities, and dietary needs. Understanding your specific stage is essential for making informed decisions about your diet and care.

If you have been told you have CKD, one of the first things your doctor will tell you is your stage. This number — based on your GFR (glomerular filtration rate) — determines nearly everything about your treatment plan, dietary needs, and prognosis. It is not just a medical classification; it is the foundation for every health decision you will make going forward.

How Are CKD Stages Determined?

CKD staging is based primarily on two measurements:

GFR (Glomerular Filtration Rate): This measures how many milliliters of blood your kidneys can filter per minute. It is calculated from a blood creatinine test combined with your age, sex, and body size. Normal GFR is 90-120+ mL/min.

Albuminuria (protein in urine): The albumin-to-creatinine ratio (ACR) in your urine indicates how much protein is leaking through damaged kidney filters. Normal is below 30 mg/g. Levels above 300 mg/g indicate significant damage.

Both numbers matter. You can have a normal GFR but still be diagnosed with CKD if you have persistent albuminuria, which indicates kidney damage even before filtering capacity drops.

Stage 1: Kidney Damage With Normal Function

GFR: 90+ mL/min | Kidney function: Normal or near-normal

Stage 1 CKD means there is evidence of kidney damage — usually protein in the urine or structural abnormalities on imaging — but your kidneys are still filtering blood at a normal rate.

Symptoms: Typically none. Most people discover Stage 1 CKD through routine lab work or testing triggered by a related condition like diabetes or hypertension.

Treatment priorities:

• Identify and treat the underlying cause
• Control blood pressure (target below 130/80 mmHg)
• Manage blood sugar if diabetic
• Begin sodium awareness (target 2,300mg/day)

Dietary changes: Minimal at this stage. The primary focus is sodium reduction and moderate protein intake (0.8g/kg body weight). Most people at Stage 1 do not need potassium or phosphorus restrictions unless lab values are abnormal.

Stage 2: Mild Reduction in Kidney Function

GFR: 60-89 mL/min | Kidney function: Mildly decreased

Stage 2 indicates a mild reduction in filtering capacity along with evidence of kidney damage.

Symptoms: Usually still none, though some people experience mild fatigue or slightly increased urination.

Treatment priorities:

• Same as Stage 1, with closer monitoring
• GFR testing every 6-12 months
• Address cardiovascular risk factors (CKD significantly increases heart disease risk)

Dietary changes: Similar to Stage 1. Sodium control remains the priority. If you have not already reduced sodium to 2,300mg/day, this is the time to make it a habit. Reading labels on everyday items like bread, canned goods, and condiments makes the biggest impact.

Important note: Many older adults have GFR values in the 60-89 range due to normal aging. A GFR of 65 in a healthy 75-year-old without proteinuria may not indicate CKD. The diagnosis requires evidence of damage (albumin in urine, structural changes) along with reduced GFR.

Stage 3: Moderate Kidney Disease

GFR: 30-59 mL/min | Kidney function: Moderately decreased

Stage 3 is often where CKD becomes “real” for patients. It is divided into two substages:

• Stage 3a: GFR 45-59 (mild-to-moderate decrease)
• Stage 3b: GFR 30-44 (moderate-to-severe decrease)

Symptoms: This is typically when symptoms begin appearing:

• Fatigue and low energy
• Swelling in hands, feet, or ankles (edema)
• Changes in urination (more frequent, foamy, or dark)
• Mild nausea or decreased appetite
• Muscle cramps
• Difficulty sleeping

Treatment priorities:

• More aggressive blood pressure management
• Possible medication changes (some drugs need dose adjustment or discontinuation)
• Referral to a nephrologist if not already seeing one
• Introduction of dietary changes
• Anemia screening and management

Dietary changes become significant:

• Sodium drops to 2,000mg/day
• Potassium monitoring begins (target 2,500mg/day)
• Phosphorus awareness starts (800mg/day), focusing on eliminating phosphorus additives
• Protein may be reduced to 0.6-0.8g/kg
• Learning food preparation techniques like leaching potatoes becomes valuable

Stage 3 is where most people begin actively managing their diet, and it is the stage where dietary intervention has the greatest potential to slow progression. A referral to a renal dietitian is strongly recommended.

Stage 4: Severe Kidney Disease

GFR: 15-29 mL/min | Kidney function: Severely decreased

Stage 4 means your kidneys have lost 70-85% of their filtering capacity. Treatment becomes more intensive, and planning for potential dialysis or transplant begins.

Symptoms are more pronounced:

• Significant fatigue
• Persistent nausea or vomiting
• Loss of appetite and metallic taste in mouth
• Swelling, especially in the legs
• Itchy skin
• Shortness of breath
• Difficulty concentrating
• Anemia (low red blood cell count)
• Bone pain or weakness (from phosphorus/calcium imbalance)

Treatment priorities:

• Discussion of renal replacement therapy options (dialysis modalities, transplant evaluation)
• Vascular access planning if hemodialysis is likely
• More frequent lab monitoring (every 1-3 months)
• Erythropoietin-stimulating agents for anemia
• Phosphorus binders with meals
• Medication review — many drugs need adjustment at this GFR

Dietary changes are the most restrictive of the pre-dialysis stages:

• Sodium: 1,500mg/day
• Potassium: 2,000mg/day
• Phosphorus: 700mg/day (the tightest restriction)
• Protein: 0.6g/kg (for a 70kg person, just 42g/day)
• Fluid may begin to be limited depending on urine output

At this stage, home cooking with fresh ingredients becomes nearly essential. Most restaurant meals and processed foods exceed sodium limits in a single serving. Meal prepping and planning ahead become critical skills.

Stage 5: Kidney Failure

GFR: Below 15 mL/min | Kidney function: Minimal or none

Stage 5 is kidney failure. Most people at this stage require dialysis or a transplant to survive.

Symptoms may include all Stage 4 symptoms plus:

• Severe fatigue and weakness
• Persistent nausea and vomiting
• Minimal or no urine output
• Severe edema
• Confusion or difficulty thinking
• Chest pain (from fluid around the heart)
• Seizures in extreme cases

Treatment: Most Stage 5 patients begin one of three paths:

• Hemodialysis: Blood is filtered by a machine, typically 3 times per week
• Peritoneal dialysis: Filtering fluid is cycled through the abdominal cavity
• Kidney transplant: A new kidney from a living or deceased donor

Each path has different dietary implications. For a detailed comparison, see our guide on peritoneal dialysis vs. hemodialysis diet differences.

Dietary changes shift significantly:

• Protein increases to 1.0-1.2g/kg (dialysis removes amino acids)
• Sodium remains at 1,500mg/day
• Potassium: 2,000mg/day (critical to manage between sessions)
• Phosphorus: 800mg/day (slightly relaxed from Stage 4)
• Fluid restriction: Often 1-1.5L total per day, including water in food

The protein increase from Stage 4 to Stage 5 is one of the most confusing aspects of kidney diet. You spend months or years restricting protein, then suddenly need to eat more. This transition requires careful guidance from your renal dietitian.

How Quickly Does CKD Progress?

Progression is not inevitable or uniform:

• Slow progressors: Some people lose less than 1 mL/min of GFR per year and remain stable in the same stage for decades
• Average progressors: Unmanaged CKD typically causes 2-5 mL/min decline per year
• Rapid progressors: Some conditions (especially uncontrolled diabetes or certain glomerular diseases) can cause 5-10+ mL/min decline per year

Factors that accelerate progression include uncontrolled blood pressure, unmanaged diabetes, high dietary sodium, smoking, obesity, and nephrotoxic medications. Factors that slow it include blood pressure control, blood sugar management, dietary adjustments, ACE inhibitors or ARBs, and SGLT2 inhibitors (a newer class of medications showing kidney-protective effects).

When to Talk to Your Doctor

Request kidney function testing if you:

• Have diabetes or hypertension
• Have a family history of kidney disease
• Notice changes in urination patterns
• Experience unexplained fatigue, swelling, or nausea
• Are taking medications that affect the kidneys
• Are over 60 and have not been screened

If you already have CKD, contact your doctor if you notice new or worsening symptoms, sudden weight gain (fluid retention), or significantly reduced urine output.

This article is for educational purposes and is not medical advice. Always consult your nephrologist for diagnosis, staging, and treatment decisions.

The Bottom Line

CKD stages are a roadmap for your care. Each stage brings specific changes in symptoms, treatment, and dietary needs. The earlier you understand your stage and begin making appropriate changes, the better your chances of slowing progression and maintaining quality of life. Diet is one of the most powerful tools you have at every stage.

KidneyPal personalizes your nutrient tracking to your CKD stage, adjusting sodium, potassium, phosphorus, and protein budgets so you always know exactly where you stand against your limits.

For detailed dietary guidance by stage, see CKD Stages and Diet. For beginners, start with our Renal Diet for Beginners guide. For a full library of kidney diet resources, visit the Kidney Disease Diet Management hub.