What Is eGFR and Why Does It Matter?
eGFR stands for estimated Glomerular Filtration Rate. It measures how well your kidneys filter waste from your blood, expressed in milliliters per minute per 1.73 square meters of body surface area (mL/min/1.73 m²).
A normal eGFR is above 90. When it drops below 60 and stays there for three months or more, it meets the clinical definition of Stage 3 Chronic Kidney Disease (CKD). This is the stage where most people first learn they have a kidney problem.
CKD Stages at a Glance
- Stage 1 (eGFR 90+): Kidney damage with normal filtration
- Stage 2 (eGFR 60-89): Mild decrease in function
- Stage 3a (eGFR 45-59): Mild to moderate decrease
- Stage 3b (eGFR 30-44): Moderate to severe decrease
- Stage 4 (eGFR 15-29): Severe decrease
- Stage 5 (eGFR below 15): Kidney failure
Stage 3 is divided into 3a and 3b because the prognosis and treatment approach differ significantly between the two. Stage 3a often remains stable for years with proper management, while Stage 3b requires closer monitoring and more aggressive intervention.
Symptoms When eGFR Falls Below 60
One of the challenges with Stage 3 CKD is that many people feel fine. Kidneys have significant reserve capacity, so symptoms are often subtle or absent until function declines further. However, some people do notice:
- Fatigue and low energy levels
- Swelling in the hands, feet, or ankles (edema)
- Changes in urination, including foamy urine or urinating more at night
- Mild nausea or loss of appetite
- Difficulty concentrating
- Muscle cramps, especially at night
- Dry, itchy skin
These symptoms overlap with many other conditions, which is why blood tests measuring creatinine and calculating eGFR are essential for accurate diagnosis.
What Causes eGFR to Drop?
The two most common causes of CKD are diabetes and high blood pressure. Together, they account for roughly two-thirds of all cases. Other causes include:
- Glomerulonephritis (inflammation of the kidney filtering units)
- Polycystic kidney disease (genetic condition)
- Prolonged use of NSAIDs (ibuprofen, naproxen)
- Recurrent kidney infections
- Obstruction from kidney stones or enlarged prostate
- Autoimmune conditions like lupus
Temporary drops in eGFR can also happen due to dehydration, certain medications, or acute illness. A single low reading does not automatically mean CKD. Your doctor will repeat the test to confirm persistence.
How to Slow CKD Progression
The most important thing to understand about Stage 3 CKD is that progression is not inevitable. Many people maintain stable kidney function for decades with proper management.
Blood Pressure Control
Keeping blood pressure below 130/80 mmHg is the single most effective way to protect remaining kidney function. ACE inhibitors and ARBs are the preferred blood pressure medications for people with CKD because they reduce pressure inside the kidney’s filtering units. You can track your readings with our Blood Pressure Calculator.
Blood Sugar Management
If you have diabetes, keeping your A1C below 7% significantly reduces kidney damage. Even small improvements in blood sugar control make a measurable difference. Use our A1C Calculator to understand your numbers.
Diet Changes for CKD Stage 3
Dietary modifications become important when eGFR drops below 60:
- Reduce sodium to less than 2,000 mg per day. This helps control blood pressure and reduce fluid retention.
- Monitor protein intake. Excessive protein creates more waste for kidneys to filter. Most nephrologists recommend 0.6 to 0.8 grams of protein per kilogram of body weight per day for Stage 3.
- Limit potassium and phosphorus if blood levels are elevated. Your doctor will monitor these through regular blood work.
- Stay hydrated but do not overdo it. Your nephrologist will advise on the right amount based on your specific situation.
Medications to Avoid
Certain medications can accelerate kidney damage:
- NSAIDs (ibuprofen, naproxen, aspirin in high doses) reduce blood flow to the kidneys
- Certain antibiotics can be toxic to the kidneys at standard doses when eGFR is reduced
- Proton pump inhibitors (omeprazole, pantoprazole) have been linked to CKD progression with long-term use
- Contrast dye used in CT scans can cause acute kidney injury when eGFR is low
Always tell every doctor and pharmacist about your kidney function before starting any new medication, including over-the-counter drugs and supplements.
What to Expect at Follow-Up Appointments
If your eGFR is between 45 and 59 (Stage 3a), your doctor will typically recheck labs every 6 to 12 months. If it falls to 30-44 (Stage 3b), expect monitoring every 3 to 6 months.
Standard follow-up labs include a comprehensive metabolic panel, urinalysis for protein, CBC for anemia, and phosphorus and parathyroid hormone levels. Your nephrologist uses these to catch complications early.
Check Your Kidney Function
Use our free calculator to estimate your eGFR based on creatinine, age, and sex. Understand your CKD stage and what it means for your health.
When to See a Nephrologist
Your primary care doctor may refer you to a nephrologist (kidney specialist) if your eGFR is below 45, declining rapidly, or accompanied by significant proteinuria. Early referral is associated with better outcomes and longer time before needing dialysis, if dialysis is ever needed at all.
An eGFR below 60 is a signal to take action, not a reason to panic. With proper blood pressure control, blood sugar management, diet modifications, and regular monitoring, many people with Stage 3 CKD maintain stable function for the rest of their lives.
