eGFR

The eGFR is determined through a simple blood test that measures serum creatinine levels, requiring no special preparation from patients [1]. This straightforward approach makes eGFR testing widely accessible and practical for routine healthcare monitoring.

The calculation uses mathematical formulas, with the most commonly used being the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation [1]. These formulas incorporate several factors:

• **Serum creatinine level**: The primary marker measured in your blood
• **Age**: Kidney function naturally declines with age
• **Sex**: Men typically have higher creatinine levels due to greater muscle mass
• **Race**: Historically included in calculations, though this is being reevaluated in current medical practice

Some laboratories may also use cystatin C, a protein that slows down the breakdown of other protein cells, either instead of or in addition to creatinine for eGFR calculation [1]. Cystatin C-based equations may provide more accurate estimates in certain populations.

The blood test itself is straightforward - a healthcare provider draws a small sample of blood from a vein in your arm. No fasting or special preparation is required, making it convenient to include in routine health screenings.

Testing frequency depends on your risk factors and current kidney function. People with diabetes, high blood pressure, or existing kidney disease may need testing every 3-6 months, while those at lower risk might be tested annually during routine physical exams [2]. Your healthcare provider will determine the appropriate testing schedule based on your individual health profile.

It's worth noting that eGFR results can fluctuate slightly between tests due to normal biological variation, temporary factors like dehydration, or recent illness [3]. Healthcare providers typically look at trends over time rather than focusing on a single result.

While the damage from chronic kidney disease is generally permanent and eGFR numbers may not return to normal levels, there are important steps you can take to protect your remaining kidney function and potentially slow disease progression [3].

**Blood Pressure Management**
Controlling blood pressure is one of the most critical factors for kidney health [2]. High blood pressure can damage the delicate filtering units in your kidneys. Aim for blood pressure targets recommended by your healthcare provider, typically below 130/80 mmHg for people with kidney disease. This may involve lifestyle changes, medications, or both.

**Blood Sugar Control**
For people with diabetes, maintaining good blood sugar control is essential for preventing further kidney damage [2]. Work with your healthcare team to achieve target hemoglobin A1C levels and monitor blood sugar regularly. Diabetes is a leading cause of kidney disease, making glucose management crucial for kidney protection.

**Physical Activity and Weight Management**
Regular physical activity brings multiple benefits for kidney health, including better blood pressure control, reduced stress levels, improved sleep, stronger muscles, and healthier weight maintenance [3]. These factors collectively support kidney function and overall cardiovascular health. Aim for at least 150 minutes of moderate-intensity exercise per week, as recommended by health guidelines.

**Medication Awareness**
Avoid non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and naproxen if you have chronic kidney disease, as these can further damage kidney function [2]. Always inform your healthcare team about all medications and supplements you're taking, and be cautious with contrast dyes used in medical imaging tests.

**Dietary Considerations**
Follow a kidney-friendly diet that includes:
• **Low sodium intake**: Reduces blood pressure and fluid retention
• **Moderate protein consumption**: Reduces workload on kidneys while maintaining adequate nutrition
• **Limited saturated fats**: Supports cardiovascular health
• **Adequate hydration**: Helps kidneys function properly, but follow your doctor's fluid recommendations if you have advanced kidney disease

**Lifestyle Factors**
Stop smoking and avoid tobacco products, as these increase the risk of kidney disease progression and cardiovascular complications [3]. Smoking reduction or cessation can help preserve remaining kidney function and improve overall health outcomes.

**Regular Monitoring**
Get your kidneys checked at least annually with both eGFR and urine albumin tests [2]. More frequent monitoring may be needed if you have existing kidney disease or risk factors. Early detection of changes allows for prompt intervention to protect kidney function.