At a Glance
Why Get Tested?
To determine the function of your kidneys. The GFR (glomerular filtration rate) is the best marker of kidney function.
When to Get Tested?
To look for evidence of kidney damage or to monitor changes in kidney function if you already have kidney disease.
eGFR is calculated using your age, gender, and serum creatinine (requires a blood sample from a vein in your arm). The calculated result is usually included on the pathology report with every request for a creatinine in adults.
The Test Sample
What is being tested?
The glomerular filtration rate (GFR) is a measure of the function of your kidneys. Glomeruli are tiny filters in your kidney that allow waste products to be removed from the blood, while preventing loss of important proteins and blood cells. The rate refers to the amount of blood that is filtered per minute.
How is the sample collected for testing?
A blood sample is taken by needle from a vein in the arm: your sex and age are taken from the patient details on your pathology request form.
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.