What is Stage 3 Kidney Disease?

Kidneys are essential organs that quietly regulate many critical functions in the body, including filtering waste, balancing fluids, controlling blood pressure, and producing hormones that support red blood cell production and bone health. When kidney function declines over time, it can lead to chronic kidney disease (CKD), a condition that affects millions of adults worldwide.

Stage 3 kidney disease represents a moderate decline in kidney function. It’s a pivotal stage because, although the kidneys are damaged, there is still an opportunity to slow or halt further progression. Understanding Stage 3 kidney disease including its causes, symptoms, diagnosis, treatment, and lifestyle strategies is crucial for protecting kidney health and overall well-being.

What do your kidneys do?

Your kidneys are two bean-shaped organs located near the middle of your back, just below the ribcage. Despite their small size, each kidney contains roughly one million tiny filtering units called nephrons, which remove waste and excess fluids from the blood.

Key kidney functions include:

• Waste removal: Filtering urea, creatinine, and other metabolic byproducts from the blood.

• Fluid and electrolyte balance: Maintaining optimal levels of sodium, potassium, and other electrolytes.

• Hormone production: Producing renin (blood pressure regulation), erythropoietin (stimulates red blood cell production), and activated vitamin D (bone health).

• Acid-base regulation: Keeping blood pH stable.

Damage to nephrons caused by high blood pressure, diabetes, infections, or other conditions reduces kidney function over time. 

What Is Stage 3 Kidney Disease?

Chronic kidney disease is classified into five stages based on glomerular filtration rate (GFR), a measure of how well kidneys filter waste from the blood.

CKD stages:

• Stage 1: GFR ≥ 90 – normal or high function with signs of kidney damage

• Stage 2: GFR 60–89 – mild loss of function

• Stage 3: GFR 30–59 – moderate loss of function

• Stage 4: GFR 15–29 – severe loss of function

• Stage 5: GFR < 15 – kidney failure

Stage 3 is further divided into:

• Stage 3a: GFR 45–59

• Stage 3b: GFR 30–44

At this stage, kidneys are functioning at 30–59% of normal capacity. While many people may feel well, moderate damage means the risk of complications increases, making monitoring and lifestyle adjustments essential.

What causes Stage 3 kidney disease?

Stage 3 kidney disease usually develops over many years due to underlying health conditions or lifestyle factors.

Common causes include:

1. Diabetes

High blood sugar damages blood vessels in the kidneys, impairing their filtering ability. Diabetic kidney disease is the leading cause of CKD worldwide.

2. Hypertension (High Blood Pressure)

Chronic high blood pressure damages small arteries in the kidneys, reducing their ability to function properly.

3. Glomerulonephritis

This refers to inflammation of the glomeruli, the tiny filtering units of the kidney. It can result from autoimmune disorders, infections, or unknown causes.

4. Polycystic Kidney Disease (PKD)

A genetic disorder where cysts form within the kidneys, impairing their structure and function over time.

5. Other Factors

• Recurrent urinary tract infections or obstructions

• Long-term use of certain medications (e.g., NSAIDs, some antibiotics)

• Autoimmune diseases (e.g., lupus)

• Prolonged dehydration or chronic kidney infections

In many people with chronic kidney disease, more than one factor contributes to kidney damage, such as a combination of diabetes, high blood pressure, and lifestyle-related risks.

What symptoms should you watch for?

Symptoms in Stage 3 are often subtle, making regular screenings vital.

Possible signs include:

• Fatigue or reduced energy

• Swelling in hands, feet, or around the eyes

• Foamy or bubbly urine (protein leakage)

• Frequent urination, especially at night

• Muscle cramps

• Dry, itchy skin

• Nausea or poor appetite

• Metallic taste in the mouth

Because these symptoms are non-specific, many people are diagnosed through routine blood tests rather than noticeable signs.

How is stage 3 kidney disease diagnosed?

Diagnosis involves a combination of blood tests, urine tests, imaging, and medical history.

1. Blood Tests

• Serum Creatinine: Elevated levels indicate reduced kidney filtration.

• Estimated GFR (eGFR): Calculated using creatinine, age, sex, and other factors.

• BUN (Blood Urea Nitrogen): Indicates waste buildup.

• Electrolyte Panel: Checks potassium, calcium, phosphorus.

2. Urine Tests

• Urine Albumin-to-Creatinine Ratio (ACR): Detects protein leakage, a sign of kidney damage.

• Urinalysis: Screens for blood, protein, or infection.

Related: What is the Normal Urine Protein/Creatinine Ratio? Its Importance in Kidney Health

3. Imaging Studies

• Ultrasound, CT scans, or MRI may reveal kidney size, structure, or obstructions.

4. Kidney Biopsy

• In select cases, a biopsy helps determine the exact cause of kidney damage.

Regular monitoring helps track disease progression, adjust treatment, and manage complications. Most patients with Stage 3 CKD have checkups every 3–6 months.

What complications can happen at this stage?

Even moderate kidney impairment can affect other body systems.

Potential complications of Stage 3 CKD:

• High blood pressure: Damaged kidneys can cause fluid and salt buildup, which increases blood pressure. In turn, high blood pressure can further harm the kidneys.

• Anemia: Healthy kidneys produce a hormone called erythropoietin, which helps make red blood cells. With CKD, lower hormone levels can lead to fatigue and weakness from anemia.

• Bone and mineral disorders: When kidneys can’t balance calcium, phosphorus, and vitamin D, bones may become weaker over time.

• Heart and blood vessel disease: CKD raises the risk of heart disease and stroke because of its impact on blood pressure, cholesterol, and inflammation.

• Electrolyte imbalances: Potassium and sodium levels may become too high or too low, which can affect muscle and heart function.

• Metabolic acidosis: Waste buildup can make the blood more acidic, potentially leading to muscle loss and bone changes.

• Swelling (edema): Extra fluid in your body can cause swelling in the feet, ankles, hands, or around the eyes.

Early recognition and management of these complications can prevent severe outcomes.

What are the treatment Options for Stage 3 Kidney Disease?

The main goals are to slow progression, manage symptoms, and prevent complications.

1. Lifestyle modifications:

• Blood pressure control: Aim for <130/80 mm Hg (individualized).

• Blood sugar management: Target HbA1c around 7%, if diabetic.

• Quit smoking: Improves kidney and cardiovascular health.

• Limit alcohol: Excess can worsen kidney function and blood pressure.

2. Medications:

• ACE inhibitors or ARBs: Protect kidneys and lower blood pressure.

• Diuretics: Reduce swelling.

• Erythropoiesis-stimulating agents: Treat anemia.

• Phosphate binders: Manage phosphorus levels.

3. Regular monitoring:

• Blood and urine tests every 3–6 months

• Blood pressure monitoring

• Vaccinations to reduce infection risk
  
  

What lifestyle habits can slow CKD progression?

Daily habits are just as important as medical treatment. You can protect your kidneys by:

1.Nutrition and Diet 

A kidney-friendly diet is crucial in Stage 3.

General guidelines:

• Protein: Moderate intake (~0.8 g/kg/day). Avoid excess.

• Sodium: Limit to 1,500–2,300 mg/day.

• Potassium: Adjust according to lab results; do not self-restrict.

• Phosphorus: Avoid processed foods with added phosphates.

• Fluids: Follow medical advice for hydration.

Healthy food choices:

• Fruits: apples, berries, grapes

• Vegetables: bell peppers, cauliflower, cabbage

• Healthy fats: olive oil, avocado

• Whole grains in moderation

Foods to limit:

• Processed meats and fast food

• Sugary drinks

• High-salt snacks

2. Exercise and Physical Activity

Physical activity supports blood pressure, weight control, and cardiovascular health.

Recommended activities:

• Walking or hiking

• Swimming or cycling

• Yoga or Pilates

Aim for 150 minutes of moderate exercise per week, with medical approval if you have other health concerns.

3. Emotional and Mental Health

A CKD diagnosis can cause anxiety or stress, even at Stage 3.

Strategies for mental well-being:

• Learn about the condition to reduce uncertainty.

• Join support groups or online communities.

• Practice stress management: meditation, deep breathing, hobbies.

• Seek counseling if anxiety or depression persists.

When to See a Doctor?

If you have Stage 3 kidney disease, regular follow-ups with your healthcare provider are a key part of managing the condition. Beyond scheduled checkups, you should see your doctor promptly if you notice any of the following:

• Sudden  or worsening swelling in the face, hands, or legs

• Rapid or unexplained weight gain

• Noticeable changes in urination patterns

• Shortness of breath or chest discomfort

• Severe fatigue, dizziness, or confusion

• Signs of infection, such as fever, chills, or painful urination

• Persistent high blood pressure despite taking medication

Related Resources

● Stage 2 Kidney Disease Life Expectancy: Basic Concepts Explained

● Early Kidney Disease and Your Eyes: Puffiness, Blurred Vision, and Beyond

● Diabetes, Foamy Urine, and Nephropathy: What’s the Link?

Final Takeaway

Stage 3 chronic kidney disease means your kidneys are filtering at about 30–59% of their normal capacity. Even at this stage, you may feel fine, but the risk of issues like high blood pressure, anemia, and bone loss is higher. Common causes include diabetes, high blood pressure, and certain genetic or inflammatory conditions.

The good news is, with the right steps, you can slow or even stop further kidney decline. Focus on keeping blood pressure and blood sugar in a healthy range, limiting excess salt and processed foods, staying hydrated, exercising regularly, and avoiding overuse of medications that strain the kidneys (like NSAIDs).

By pairing regular checkups with a kidney-friendly lifestyle, you can protect your kidney function, lower your risk of complications, and maintain long-term health.

Take control of your kidney health today—learn how to manage Stage 3 CKD, prevent complications, and protect your future. Start making changes now with Ribbon Checkup’s at-home kidney health test!

References

References

Chronic kidney disease - Symptoms and causes. (2025). Mayo Clinic; https://www.mayoclinic.org/diseases-conditions/chronic-kidney-disease/symptoms-causes/syc-20354521 

Felman, A. (2023, August 14). What to know about stage 3 kidney disease. Medicalnewstoday.com; Medical News Today. https://www.medicalnewstoday.com/articles/stage-3-kidney-disease?utm_source=chatgpt.com 

Neild, G. H. (2016). Life expectancy with chronic kidney disease: an educational review. Pediatric Nephrology, 32(2), 243–248. https://doi.org/10.1007/s00467-016-3383-8 

NHS website. (2017, October). Chronic kidney disease. Nhs.uk. https://www.nhs.uk/conditions/kidney-disease/ 

Stage 3 chronic kidney disease (CKD) causes, symptoms and treatment. (2021, October 29). American Kidney Fund. https://www.kidneyfund.org/all-about-kidneys/stages-kidney-disease/stage-3-chronic-kidney-disease-ckd-causes-symptoms-and-treatment?utm_source=chatgpt.com