Kidney tests (also called KFT or RFT) measure waste products, salts and minerals in your blood to show how well your kidneys filter and balance them.
Why is it done?
They are checked at routine health checks, in diabetes and high blood pressure, before and during many medicines, and when someone has swelling or changes in urination.
How to prepare
Fasting is not usually needed. Avoid a large meat meal and creatine supplements the day before, and drink normally.
How to read your results
Creatinine and eGFR are the key numbers: a high creatinine and low eGFR mean reduced kidney function. BUN rises with dehydration and protein intake. Sodium, potassium and other electrolytes must stay in narrow ranges. Urine microalbumin catches kidney damage earliest.
Tests in this panel and their normal ranges
| Test | Normal range (adults) |
|---|---|
| Cystatin C | 0.6–1 mg/L |
| Uric Acid | Men 3.5–7.2 mg/dL (208–428 µmol/L) Women 2.5–6 mg/dL (149–357 µmol/L) |
| Sodium (Na) | 135–145 mmol/L |
| Potassium (K) | 3.5–5 mmol/L |
| Chloride (Cl) | 96–106 mmol/L |
| Bicarbonate (CO₂) | 23–29 mmol/L |
| Calcium | 8.5–10.2 mg/dL (2.12–2.54 mmol/L) |
| Phosphate (Phosphorus) | 2.5–4.5 mg/dL (0.81–1.45 mmol/L) |
| Urine Microalbumin (ACR) | Below 30 mg/g (below 3.4 mg/mmol) |
Ranges vary slightly between laboratories. The range printed on your own report is the one to go by.
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This page is for general education and is not a diagnosis. Normal ranges differ between laboratories, so always compare your result with the reference range printed on your own report, and discuss abnormal results with your doctor.