What the Kidney Function Test (KFT) measures
A kidney function test (KFT) measures substances in the blood that healthy kidneys keep in balance. Urea and creatinine are waste products that the kidneys filter out; when kidney function falls, their levels rise. From the creatinine value, together with age and sex, the laboratory calculates the eGFR (estimated glomerular filtration rate), which is the usual way of describing how well the kidneys are filtering. Uric acid is linked with gout and kidney stones. Calcium and phosphorus reflect mineral balance, which the kidneys help to control. Sodium, potassium and chloride are electrolytes; abnormal levels can follow vomiting, diarrhoea, some blood pressure and water tablets, or kidney disease, and potassium in particular matters for the heart. Doctors check kidney function regularly in people with diabetes or high blood pressure, because these are common causes of long-term kidney damage that may cause no symptoms early on, and before or during treatment with medicines cleared by the kidneys.
Price: the Kidney Function Test (KFT) costs ₹464 at Pure Bliss (MRP ₹580), with the sample collected at our Action Area 2, New Town centre or at your home.
Who this test is for
- People with diabetes or high blood pressure, as part of regular follow-up
- Swelling of the feet or face, passing much less urine, or frothy urine
- Before or during treatment with medicines that affect the kidneys
- Routine health check-ups
How to prepare, the sample, and when to expect the report
Preparation
Fasting is not strictly required for most of these tests, but an overnight fast is often advised when the KFT is booked with sugar or lipid tests. Avoid heavy exercise and a very high-protein meal the day before, as both can raise creatinine slightly. Keep taking your usual medicines unless your doctor says otherwise.
Sample
Blood, from a vein in the arm (serum).
Reporting time
Morning samples are reported the same day; later samples by the next day.
Reading the result
Reference ranges differ between laboratories, so your report lists the laboratory’s own range beside each value. A result outside the range does not always mean illness; ask your doctor to explain it.
- Centre or home collection
- NABL-accredited Redcliffe Labs collection centre
- How collection works →