Learn about eGFR and its normal range for different age groups

Estimated Glomerular Filtration Rate, commonly known as eGFR, is a blood test result that estimates how much blood your kidneys filter per minute. It is calculated using your creatinine levels, age, sex, and sometimes race. Doctors use this number to assess kidney function and detect early signs of chronic kidney disease (CKD). Because kidney function naturally shifts over a lifetime, understanding eGFR in context is essential for accurate interpretation.

This article is for informational purposes only and should not be considered medical advice. Please consult a qualified healthcare professional for personalized guidance and treatment.

General Normal eGFR Ranges and CKD Staging

In general, an eGFR of 90 or above is considered normal kidney function, assuming there are no other signs of kidney damage such as protein in the urine. The National Kidney Foundation uses eGFR as the primary marker to classify CKD into five stages. Stage 1 involves normal or high eGFR (90+) with other signs of kidney damage. Stage 2 ranges from 60 to 89, Stage 3 from 30 to 59, Stage 4 from 15 to 29, and Stage 5, also called kidney failure, falls below 15. These thresholds apply broadly but must always be interpreted alongside other clinical findings and patient history.

Normal eGFR Ranges by Age

One important and often overlooked factor is that eGFR values naturally decline with age. A healthy young adult may have an eGFR well above 100, while a healthy older adult may have a reading in the 60s or 70s. The following gives a general overview of typical ranges across age groups:

These values reflect average estimates and may vary depending on overall health, hydration, and underlying conditions. A single low reading does not automatically indicate kidney disease, especially in older adults whose kidneys naturally lose some filtration efficiency over time.

What Do Abnormal eGFR Levels Mean

An eGFR below 60 that persists for three months or more is generally considered a marker of chronic kidney disease, regardless of the underlying cause. Values between 45 and 59 suggest a moderate decrease in kidney function and warrant regular monitoring. Readings below 30 indicate a significant loss of function, and values under 15 typically signal the need for dialysis or transplant evaluation. On the other end, an unusually high eGFR can sometimes point to conditions like diabetes in its early stages, where the kidneys are working harder than normal. It is worth noting that eGFR is an estimate and can be affected by muscle mass, diet, certain medications, and acute illness, which is why healthcare providers often look at trends over time rather than isolated numbers.

How to Maintain or Improve Kidney Health and eGFR

While some causes of reduced eGFR, such as aging or genetic conditions, cannot be fully reversed, there are meaningful lifestyle changes that can help protect kidney function and in some cases lead to modest improvements in eGFR. Staying well hydrated supports the kidneys in filtering waste efficiently. Controlling blood pressure and blood sugar levels is critical, as hypertension and diabetes are the two leading causes of kidney disease in the United States. A diet lower in sodium, processed foods, and excessive protein reduces the workload on the kidneys. Regular physical activity, avoiding smoking, and limiting over-the-counter pain medications such as NSAIDs are also important protective measures. People diagnosed with early-stage CKD often work with a nephrologist and a renal dietitian to develop a plan tailored to their specific eGFR levels and health history.

Keeping track of your eGFR over time, maintaining regular medical appointments, and addressing risk factors early are among the most practical steps you can take toward long-term kidney health. Even small changes in lifestyle can have a meaningful impact on slowing disease progression and preserving quality of life.