Understanding eGFR (estimated Glomerular Filtration Rate) normal values is crucial for assessing kidney health. This comprehensive guide explains what constitutes normal eGFR values across different demographics and the various factors that can influence your test results.

What is eGFR?

The estimated Glomerular Filtration Rate (eGFR) is a key indicator of kidney function, measured in milliliters per minute per 1.73 square meters of body surface area (mL/min/1.73m²). It estimates how well your kidneys are filtering waste from your blood.

eGFR Normal Values

Normal Range: eGFR ≥90 mL/min/1.73m² indicates normal kidney function

Age Factor: eGFR naturally declines with age, approximately 1 mL/min/1.73m² per year after age 30

Need to check your kidney function? Use our free eGFR calculator for instant results based on your lab values.

eGFR Categories and Kidney Function Stages

Healthcare professionals use standardized eGFR ranges to classify kidney function into different stages:

eGFR Range Stage Kidney Function Description
≥90 G1 Normal or High Normal kidney function
60-89 G2 Mildly Decreased Mild reduction in kidney function
45-59 G3a Moderately Decreased Mild to moderate decrease
30-44 G3b Moderately Decreased Moderate to severe decrease
15-29 G4 Severely Decreased Severe decrease in function
<15 G5 Kidney Failure Kidney failure requiring treatment

eGFR Normal Values by Age

Age is the most significant factor affecting eGFR values. Kidney function naturally declines with age, even in healthy individuals:

Age Group Average eGFR Normal Range Notes
20-29 years 116 90-140 Peak kidney function
30-39 years 107 80-130 Slight decline begins
40-49 years 99 70-120 Gradual decline continues
50-59 years 93 65-115 More noticeable decline
60-69 years 85 60-110 Significant age-related decline
70+ years 75 50-100 Substantial decline, may be normal for age

Factors Affecting eGFR Results

Several factors can influence eGFR calculations and results. Understanding these factors is crucial for proper interpretation:

Demographic Factors

  • Gender: Men typically have higher eGFR values due to greater muscle mass and higher creatinine production.
  • Ethnicity: Different ethnic groups may have varying baseline creatinine levels affecting eGFR calculations.
  • Body Size: eGFR is normalized to body surface area, which may not accurately reflect kidney function in very large or small individuals.
  • Muscle Mass: Higher muscle mass leads to higher creatinine production, potentially affecting eGFR accuracy.

Medical and Lifestyle Factors

Factors That Can Lower eGFR

  • Dehydration
  • Certain medications (NSAIDs, ACE inhibitors)
  • High protein diet
  • Intense exercise
  • Acute illness or fever
  • Pregnancy

Factors That Can Raise eGFR

  • Low muscle mass
  • Vegetarian diet
  • Certain medications (cimetidine)
  • Amputation
  • Malnutrition

Interpreting Your eGFR Results

Understanding your eGFR results requires considering multiple factors beyond just the numerical value:

eGFR ≥90: Normal Function

Continue healthy lifestyle habits. Regular check-ups as recommended by your doctor.

eGFR 60-89: Mild Decrease

Monitor kidney health. Address risk factors like diabetes and high blood pressure.

eGFR 30-59: Moderate Decrease

Work closely with your healthcare team. Consider nephrology referral.

eGFR <30: Severe Decrease

Immediate medical attention needed. Prepare for possible kidney replacement therapy.

When eGFR May Not Be Accurate

eGFR calculations may not be reliable in certain populations:

  • Children under 18 years old
  • Pregnant women
  • People with unusual muscle mass (very high or very low)
  • Amputees
  • People with severe malnutrition
  • Vegetarians with very low protein intake

Ready to calculate your eGFR? Our eGFR calculator tool provides instant results with detailed interpretation based on your age, gender, and lab values.

Maintaining Healthy Kidney Function

Regardless of your current eGFR, these steps can help maintain or improve kidney health:

Stay Hydrated

Drink adequate water to help kidneys filter waste effectively.

Control Blood Pressure

High blood pressure is a leading cause of kidney damage.

Manage Diabetes

Keep blood sugar levels within target range to protect kidneys.

Avoid Nephrotoxic Medications

Use NSAIDs and other kidney-damaging drugs sparingly.

Conclusion

Understanding eGFR normal values and the factors that affect them is essential for monitoring kidney health. While eGFR naturally declines with age, maintaining a healthy lifestyle can help preserve kidney function. Always work with your healthcare provider to interpret your results in the context of your overall health and medical history.

Regular monitoring of eGFR, especially if you have risk factors for kidney disease, can help detect problems early when treatment is most effective. Remember that a single abnormal result doesn't necessarily indicate kidney disease – trends over time are more important than individual values.

Ready to check your kidney function? Our eGFR calculator tool provides instant, accurate results with comprehensive interpretation based on the latest medical guidelines.