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Kidney function test (KFT) report: creatinine, urea, eGFR explained
A kidney function test, printed as KFT or RFT (renal function test), checks how well your kidneys filter waste from the blood. Creatinine and the eGFR calculated from it are the key values.
What each value means
| On your report | What it measures | Typical adult range |
|---|---|---|
| Serum creatinine | Waste from muscles, cleared by the kidneys | Men 0.7–1.3 mg/dL; women 0.6–1.1 mg/dL |
| eGFR | Estimated filtering rate, calculated from creatinine | 90 or above is normal (mL/min/1.73m²) |
| Blood urea | Waste from protein breakdown | About 15–40 mg/dL |
| BUN | The nitrogen part of urea | About 7–20 mg/dL |
| Uric acid | Waste from purines in food and cells | Men 3.5–7.2 mg/dL; women 2.6–6.0 mg/dL |
| Sodium | Salt balance | 135–145 mmol/L |
| Potassium | Important for heart and muscles | 3.5–5.1 mmol/L |
| Chloride | Salt and acid balance | 98–107 mmol/L |
Ranges differ between laboratories, machines, age groups and in pregnancy. The range printed on your own report is the one that applies to you.
Reading creatinine and eGFR together
Creatinine depends on muscle mass, so a well-built person may run slightly higher and an elderly person lower. That is why labs calculate eGFR, which adjusts for age and sex. Doctors look at eGFR over time: a single low reading, especially after dehydration or a heavy workout, is often repeated.
Uric acid
Uric acid is often printed with kidney tests. A high value may relate to diet, alcohol, some medicines and kidney function, and is linked with gout, but many people with a high value never have symptoms.
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Read my reportCommon questions
What is the normal creatinine level?
Commonly about 0.7–1.3 mg/dL for men and 0.6–1.1 mg/dL for women. It varies with muscle mass, so read it with eGFR and your lab's range.
What is eGFR?
eGFR is an estimate of how much blood your kidneys filter each minute, calculated from creatinine, age and sex. A value of 90 or more is generally normal.
Does drinking water change kidney test results?
Being dehydrated can raise urea and creatinine slightly. Drink normally before the test unless your lab tells you otherwise.
Other lab test guides
Complete blood count (CBC) · Thyroid profile (TSH, T3, T4) · Lipid profile (cholesterol test) · Liver function test (LFT) · HbA1c and blood sugar tests · Vitamin D and vitamin B12 tests
This guide is general information for adults, not medical advice and not a diagnosis. Only a qualified doctor can interpret your results. Updated 2026-10-06. See the medical disclaimer.