If you recently had blood work performed and noticed a number called eGFR on your lab report, you may be wondering what it means and whether you should be concerned.
The estimated Glomerular Filtration Rate (eGFR) is one of the most important measurements used to evaluate kidney function. Healthcare providers across Canada use eGFR to help identify chronic kidney disease (CKD), monitor kidney health, and determine whether further evaluation by a nephrologist may be needed.
Understanding your eGFR results can help you take a more active role in protecting your kidney health.
What Does eGFR Mean?
eGFR stands for Estimated Glomerular Filtration Rate.
It estimates how effectively your kidneys are filtering waste products and excess fluid from your blood. Healthy kidneys continuously remove toxins and waste from the body while maintaining proper fluid and electrolyte balance.
When kidney function declines, the filtration rate may decrease, resulting in a lower eGFR.
The eGFR calculation is based on several factors, including:
- Serum creatinine level
- Age
- Sex
- Body characteristics
Because eGFR provides an estimate rather than a direct measurement, it is usually interpreted alongside other blood and urine tests.
Why is eGFR Important?
eGFR is one of the most valuable tools for detecting kidney disease early.
Many people with chronic kidney disease do not experience symptoms during the early stages. In many cases, an abnormal eGFR may be the first indication that kidney function is declining.
Doctors use eGFR to:
- Assess kidney function
- Diagnose chronic kidney disease
- Monitor disease progression
- Evaluate treatment effectiveness
- Guide medication decisions
- Determine when specialist referral is appropriate
Understanding Your eGFR Results
eGFR 90 or Higher
An eGFR of 90 or above is generally considered normal if no other evidence of kidney disease is present.
eGFR 60–89
This range may indicate mildly reduced kidney function in some individuals. Additional testing may be necessary to determine whether kidney disease is present.
eGFR 45–59
This range often suggests moderate kidney impairment and may require ongoing monitoring.
eGFR 30–44
This level represents more significant kidney dysfunction and typically requires closer follow-up.
eGFR 15–29
This indicates severe kidney disease and requires specialist nephrology care.
eGFR Below 15
This may indicate kidney failure and requires urgent evaluation and management by a nephrologist.
Can eGFR Change?
Yes.
eGFR can fluctuate based on several factors, including:
- Hydration status
- Recent illness
- Certain medications
- Blood pressure changes
- Acute kidney injury
- Laboratory variation
For this reason, doctors often look at trends over time rather than relying on a single result.
What Causes a Low eGFR?
A lower-than-normal eGFR may occur because of:
Chronic Kidney Disease
CKD is one of the most common causes of declining kidney function.
Diabetes
Diabetes is a leading cause of kidney disease in Canada and can gradually damage the kidneys over time.
High Blood Pressure
Poorly controlled blood pressure can damage the kidneys and contribute to declining eGFR.
Glomerulonephritis
Inflammation of the kidney’s filtering units can affect kidney function.
Polycystic Kidney Disease
This inherited condition can reduce kidney function over time.
Kidney Injury
Acute illness, infections, dehydration, or medication-related kidney injury can temporarily affect eGFR.
What Other Tests Should Be Reviewed Alongside eGFR?
eGFR should never be interpreted in isolation.
Additional kidney tests often include:
Creatinine
Creatinine is a waste product filtered by the kidneys. Elevated creatinine levels often correspond with lower eGFR values.
Urine Albumin-to-Creatinine Ratio (ACR)
This test measures protein leakage into the urine and can help identify early kidney damage.
Urinalysis
Urine testing can detect blood, protein, infection, and other abnormalities.
Blood Pressure
High blood pressure and kidney disease are closely linked.
When Should You See a Nephrologist?
You may benefit from seeing a nephrologist if you have:
- Persistently low eGFR
- Chronic kidney disease
- Protein in your urine
- Blood in your urine
- Diabetic kidney disease
- Resistant high blood pressure
- Rapidly declining kidney function
Early evaluation can help identify the cause of kidney dysfunction and develop an appropriate treatment plan.
How Dr. Shahzad Can Help
Dr. Shahzad provides virtual nephrology consultations for patients throughout British Columbia, including Surrey and surrounding communities.
If you have concerns about:
- Low eGFR
- Elevated creatinine
- Chronic kidney disease
- Diabetic kidney disease
- Protein in the urine
- Abnormal kidney blood work
Dr. Shahzad can review your laboratory results, explain what they mean, assess your overall kidney health, and develop a personalized management plan tailored to your needs.
Through secure virtual consultations, patients can discuss kidney test results from the comfort of their homes while receiving expert nephrology guidance.
Tips to Protect Your Kidney Function
Regardless of your current eGFR, the following habits may help support kidney health:
- Control blood sugar if you have diabetes
- Maintain healthy blood pressure
- Stay physically active
- Follow a balanced diet
- Avoid smoking
- Take medications as prescribed
- Attend regular medical follow-up appointments
- Monitor kidney function when recommended
Frequently Asked Questions
What is a normal eGFR?
In most adults, an eGFR of 90 or higher is generally considered normal when no other evidence of kidney disease exists.
Does a low eGFR always mean kidney disease?
Not necessarily. Temporary illness, dehydration, medications, and other factors can affect eGFR results. Your healthcare provider will evaluate the overall clinical picture.
Can eGFR improve?
In some situations, eGFR may improve if the underlying cause is identified and treated. However, chronic kidney disease often requires long-term monitoring and management.
How often should eGFR be checked?
The frequency depends on your medical history, kidney function, diabetes status, and risk factors for kidney disease.
Can I discuss my eGFR results with a nephrologist virtually?
Yes. Virtual nephrology consultations are an effective way to review kidney blood work, discuss abnormal results, and receive specialist recommendations.