GFR (Glomerular Filtration Rate)
The purpose of this test is to:
- Estimate kidney filtration function (GFR/eGFR)
- Detect early signs of kidney disease
- Monitor progression of chronic kidney disease (CKD)
- Assess overall kidney health
- Support treatment planning and monitoring
GFR (GLOMERULAR FILTRATION RATE) Test
The GFR (Glomerular Filtration Rate) estimates how efficiently the kidneys filter waste and excess fluid from the blood. It is one of the most important measures used to assess kidney function. In routine practice, GFR is usually estimated (eGFR) from blood creatinine along with factors such as age and sex, rather than measured directly.
A lower eGFR can indicate reduced kidney filtration and may be associated with chronic kidney disease (CKD). Healthcare providers use eGFR together with other findings, particularly urine albumin or albumin-to-creatinine ratio (ACR), to evaluate kidney health and determine the severity of kidney disease.
GFR can also be monitored over time to assess whether kidney function is stable, improving, or declining. A single abnormal value does not necessarily confirm chronic kidney disease because eGFR can be affected by factors such as acute illness, changes in creatinine, hydration, and certain medicines.
This Test is Recommended for Individuals:
- Individuals undergoing a routine kidney health assessment
- People with elevated serum creatinine
- Individuals with suspected or known chronic kidney disease
- People with diabetes or high blood pressure
- Individuals with a family history of kidney disease
- People with conditions that may affect kidney function
- Patients taking medicines that require monitoring of kidney function
- Individuals being monitored for progression of existing kidney disease
- Patients whose healthcare provider recommends assessment of renal filtration function
FAQs
1. What does a low GFR indicate?
A persistently reduced eGFR may indicate reduced kidney function. However, interpretation depends on the actual value, duration of the reduction, urine findings, age, and other clinical factors. A single low result does not automatically mean chronic kidney disease.
2. Is GFR calculated from a blood test?
Yes. In routine testing, eGFR is usually calculated using serum creatinine and other patient information. Some newer equations may also incorporate cystatin C when appropriate.
3. How often should GFR be checked?
The frequency depends on your kidney health and risk factors. People with CKD, diabetes, hypertension, or other kidney-related risks may need regular monitoring, while healthy individuals may have kidney function assessed as part of routine medical testing. Your healthcare provider can recommend the appropriate interval.