Kidney Function Test Reference Guide
A kidney function test (KFT or RFT) checks how well your kidneys clear waste and balance salts. This guide explains each value.
The Kidney Function Test Reference Guide is being built
This free reference guide will appear here shortly. Meanwhile, the formula and ranges below show exactly how it works.
- KFT parameter or report values
- Age
- Sex
- Meaning of each value
- Low / normal / high
About the Kidney Function Test Reference Guide
Kidney disease is often silent until it is advanced. People with diabetes or high blood pressure should test at least yearly.
Reference ranges & how it works
Typical adult ranges (lab-dependent):
Creatinine: men 0.7–1.3 · women 0.6–1.1 mg/dL
Urea: 15–40 mg/dL (BUN 7–20 mg/dL; BUN = urea ÷ 2.14)
Uric acid: men 3.4–7.0 · women 2.4–6.0 mg/dL
Sodium: 135–145 · Potassium: 3.5–5.1 · Chloride: 98–107 mEq/L
eGFR: 90+ normal
Frequently asked questions
What raises creatinine levels?
Kidney disease, dehydration, heavy exercise, high meat intake and some medicines. Muscular people naturally have higher creatinine.
Is high uric acid a kidney problem?
Not always. High uric acid can come from diet, alcohol, some medicines or reduced kidney clearance, and can cause gout or kidney stones.
Medical disclaimer: These tools give general information and estimates only. They are not a diagnosis and do not replace advice from a qualified doctor. Always talk to your doctor about your results, and seek urgent medical help in an emergency.