Kidney Function Test (KFT): Purpose, Normal Values, and Health Insights

Kidneys are critical to maintaining health in the body. They filter out wastes from the blood, get rid of any extra water in the body and maintain proper balance of minerals. If kidney function falls, waste products can build up in the blood. A KFT is performed to assess how well the kidneys are working and to look for problems. We offer diagnostic tests to help your doctor assess kidney function at Molecular Diagnostics and Therapy.

What Is a Kidney Function Test (KFT)?

A Kidney Function Test (also known as a KFT) is a series of blood tests and sometimes urine tests to help assess the condition of your kidneys. It looks at creatinine, urea, and electrolytes to help provide insight into how well the kidneys are functioning by looking at their levels in the blood. A doctor may recommend a KFT if you have symptoms of kidney disease, diabetes, high blood pressure, or a family history of kidney disease. You may also be advised to have regular tests as part of a routine health check, or to monitor a known kidney condition. 

Why Is a KFT Test Performed?

A KFT may assist your doctor in assessing kidney function. If you are at higher risk, regular testing is important. A KFT shows how well your kidneys are filtering waste. It can also indicate dehydration, chronic conditions, and aid in the identification of the effects of medication on the kidneys. Having regular KFTs can help those diagnosed with kidney disease to see how their kidney function is changing over time. If you have diabetes and/or high blood pressure, your kidney checks may need to be regular, because these may lead to damage to the small blood vessels in the kidney. Finding kidney problems early helps doctors recommend the right treatment.

Normal Kidney Function Test Values

Normal levels can vary depending on age, gender, muscle size, lab, and individual health. Below is a general guide:

• Serum creatinine levels are typically between 0.6mg/dL and 1.3mg/dL in adults. Urea levels are typically between 15mg/dL and 40mg/dL. BUN levels can range from 7mg/dL to 20mg/dL. Uric acid levels are typically between 3.5mg/dL and 7.2mg/dL in males and 2.6mg/dL to 6.0mg/dL in females.
  Note : Urea and blood urea nitrogen (BUN) both reflect urea-related waste in the blood, but they measure and report it differently, so their numerical values and reference ranges are not interchangeable. 
• Sodium levels are typically between 135mmol/L and 145mmol/L. Potassium levels are between 3.5mmol/L and 5.0mmol/L. Chloride levels are typically between 98mmol/L and 106mmol/L. An eGFR of 90 mL/min/1.73 m² or above is generally considered normal or high in adults, provided there are no other signs of kidney damage.

These are just general guidelines. Always use the reference range printed on your own report. Chronic kidney disease (CKD) is diagnosed when abnormalities of kidney structure or function persist for at least 3 months and have health implications. This includes an eGFR below 60 mL/min/1.73 m² or other markers of kidney damage, such as persistent albumin in the urine. Other tests, such as urine albumin, also help diagnose kidney disease. 

How to Understand a KFT Report?

Your KFT report will display how much is each of the parameters and what the reference range is. If levels are not in this range, this will be stated as "high" or "low". For instance, if the creatinine or urea level is high, this may mean your kidneys are not working as they should. If your eGFR is low, this may mean that your kidneys have a smaller filtering capacity.

But do not interpret the results on your own. Some variables may be influenced by dehydration, recent illness, diet, the size of the muscle, and medications. Your doctor may also suggest additional blood or urine tests to gain a better understanding of the function of your kidneys. For instance, an albumin-to-creatinine ratio in urine.

Kidney Function Test Cost

The cost of a kidney function test depends on the number of parameters tested. A basic KFT includes creatinine, urea, and electrolytes, and a more detailed package may include more tests. Check which tests are included in your package, and ask whether fasting is required. Please contact Molecular Diagnostics and Therapy for information on appointments and pricing.

Conclusion

KFT, or Kidney Function Test, is one significant test that can be used to assess the function of your kidneys. Your doctor may also use certain blood and urine tests to get a better idea of the health of your kidneys, including tests for creatinine, urea, uric acid, electrolytes, and eGFR. Regular testing is especially important for people with diabetes, high blood pressure, or kidney disease. Molecular Diagnostics and Therapy offers diagnostic testing to support timely evaluation. Discuss your KFT result with your doctor to see whether there is a need to have any more tests or treatment.