Why get tested?
To assess kidney function

When to get tested?
If your doctor thinks that you may have kidney damage

Sample required?
The eGFR is a calculated estimate of the actual glomerular filtration rate and is based on your serum creatinine concentration, which requires a blood sample from a vein in your arm; the calculation uses a formula that also can include your age, gender, height, and weight; in some formulas, race may also be used in the calculation