eGFR: What Your Results Mean
Bottom line: eGFR estimates how well your kidneys filter waste. Normal is 90+ mL/min. Lower values indicate reduced kidney function.
What Is eGFR (Estimated Glomerular Filtration Rate)?
The Estimated Glomerular Filtration Rate, or eGFR, is a blood test that estimates how well your kidneys are working to filter waste products from your blood. Your kidneys contain millions of tiny filters called glomeruli, which are responsible for cleaning your blood. The eGFR calculates the volume of blood that these filters can clear of waste products per minute. It's expressed in milliliters per minute per 1.73 square meters of body surface area (mL/min/1.73m²), which is a standard size to account for differences in body size.
This test is crucial because it provides a numerical estimate of your kidney function and is a key indicator for detecting and managing chronic kidney disease (CKD). A lower eGFR generally suggests that your kidneys are not filtering waste as efficiently as they should, which could be an early sign of kidney damage. Regularly monitoring your eGFR helps healthcare providers track the progression of kidney disease and adjust treatment plans to protect your kidney health.
eGFR (Estimated Glomerular Filtration Rate) Reference Ranges
| Classification | Range (mL/min/1.73m²) |
|---|---|
| Very Low (Severe CKD) | < 15 |
| Low (Moderate to Severe CKD) | 15 - 29 |
| Low-Normal (Mild CKD) | 30 - 59 |
| Normal | 60 - 89 |
| High (May indicate overhydration or specific conditions) | > 90 |
What Affects Your eGFR (Estimated Glomerular Filtration Rate) Levels?
- Age
- Sex
- Race/Ethnicity
- Muscle mass (influenced by diet, exercise, and certain medical conditions)
- Pregnancy
- Certain medications
- Diet (e.g., high protein intake)
- Body size and composition
When to Get Tested
Your doctor may order an eGFR test as part of a routine physical examination, especially if you have risk factors for kidney disease. This includes individuals with diabetes, high blood pressure, a family history of kidney disease, heart disease, or if you are older than 60. It's also ordered if you have symptoms that could suggest kidney problems, such as swelling in your legs or feet, changes in urination, fatigue, or nausea. The eGFR is essential for diagnosing and monitoring the progression of chronic kidney disease (CKD). It helps healthcare providers determine the stage of CKD and guide treatment to slow down or prevent further kidney damage. If you have any underlying conditions that can affect kidney function, regular eGFR monitoring is often recommended.
Look Up Your eGFR (Estimated Glomerular Filtration Rate) Result
Select your value below to see a detailed breakdown of what it means:
Read the Full Blood Test Guide
Frequently Asked Questions
A low eGFR indicates that your kidneys are not filtering waste products from your blood as efficiently as they should. This could be a sign of acute kidney injury or chronic kidney disease (CKD).
The formulas used to estimate GFR (like the CKD-EPI or MDRD formula) incorporate your age, sex, and sometimes race because these factors can influence kidney function and the amount of creatinine produced in your body, which is a key component of the calculation.
If your eGFR is low due to a temporary cause, such as dehydration or a specific medication, it may improve once the underlying issue is resolved. However, if the damage to your kidneys is chronic and significant, a low eGFR may not be fully reversible.
