Kidney Function Test (RFT)

Here is the uncomfortable fact about kidneys: you can lose a large share of their function before you feel anything at all. No pain. No obvious symptom. By the time swelling in the ankles or persistent tiredness sends someone to a doctor, the damage has usually been accumulating for years.

A Renal Function Test, also called a Kidney Function Test or RFT, measures how well your kidneys are filtering waste from your blood, balancing your body's salts and water, and helping control blood pressure.

Doctors order it for diabetes, the leading cause of kidney failure, for high blood pressure, for swelling of the feet or face, for changes in urination, for persistent tiredness without another explanation, before starting certain medicines, for long-term painkiller use, for a family history of kidney disease, and as part of routine annual screening.

For anyone in Gujranwala living with diabetes or high blood pressure, this is the test that catches kidney damage early enough to act.

• No fasting is required for a kidney function test on its own. If it has been ordered alongside a lipid profile or fasting blood sugar, follow the fasting rule for those and book a morning slot.
• Drink water normally in the days before. Do not deliberately over-hydrate or under-hydrate, since dehydration raises urea and creatinine and produces a falsely worrying report.
• Avoid a very high-protein meal the evening before, including large quantities of red meat, as it can temporarily raise urea.
• Avoid heavy exercise for 24 hours. Intense activity releases creatinine from muscle and can push the value up independently of your kidneys.
• List all your medicines. NSAIDs, certain antibiotics, blood pressure medicines and diuretics all affect these numbers.
• Mention any recent contrast scan. Contrast dye used in CT scans temporarily affects kidney values.