Test Detail
Understanding the Test
Test Measures
Interpreting Results
Other Tests
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Dr. Nitika Vashisht
MD Pathology, MBBS
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KFT (Kidney Function Test)

Also known as RFT (Renal Function Test)
KFT (Kidney Function Test) Includes 3 testsView All
You need to provide
This test is for
Male, Female
Test Preparation
  1. No special preparation is required.

Understanding KFT (Kidney Function Test)

What is KFT (Kidney Function Test)?

The KFT (Kidney Function Test), also known as Renal Function Test (RFT), evaluates how well your kidneys function, diagnoses any kidney disease or damage and monitors the treatment response of an ongoing condition of the kidneys. KFT/RFT may be done if you experience symptoms such as frequent urination, bloody urine, muscle cramps, or sharp pain in your groin. This test is also done as part of routine health checkups.

The kidneys play a vital role in removing waste, toxins, and extra water from the body. They are responsible for maintaining a healthy balance of water, salts, and minerals such as calcium, sodium, potassium, and phosphorus. They are also essential for blood pressure control, maintenance of the body’s pH balance, making red blood cell production hormones, and promoting bone health. Hence, keeping your kidneys healthy is essential for maintaining overall health.

The KFT (Kidney Function Test) helps with the early detection of kidney problems, such as kidney stones, kidney failure, or kidney infections. This early detection allows your doctor to plan the treatment timely and prevent future complications. KFT/RFT also helps monitor any known kidney problems, track the recovery process if you are already getting treated for the same, and determine if you need dose adjustments of certain medicines you might be taking for other diseases. Your doctor may also advise this test if you have risk factors for any kidney condition, such as obesity, diabetes, excessive alcohol consumption, or a family history of kidney disease.

Usually, no special preparation is required for this test. You may eat and drink as per your daily routine. Test result ranges are approximate and may differ slightly between labs depending on the methodology and laboratory guidelines. Talk to your doctor about your specific test results. Narrate your complete medical history to help the doctor correlate your clinical and laboratory findings. The results will help them determine your medical condition, make recommendations for lifestyle modifications such as diet and exercise, decide whether or not medication will be required to manage your kidney health and formulate your overall treatment plan.

What is KFT (Kidney Function Test) used for?

The KFT (Kidney Function Test) is done:

  • As part of routine health checkups.
  • To help detect any disease affecting the kidneys.
  • To screen for kidney disease if you have risk factors like obesity, diabetes, high blood pressure, or a family history of kidney disease.
  • To monitor the treatment response of kidney diseases.
  • To monitor for the side effects of medications such as nonsteroidal anti-inflammatory drugs (ibuprofen, naproxen), antibiotics (vancomycin), ACE inhibitors (lisinopril, enalapril), and diuretics (furosemide, hydrochlorothiazide).

What does KFT (Kidney Function Test) measure?

Contains 3 tests

The KFT (Kidney Function Test) comprises a series of blood tests that collectively determine the health of your kidneys. KFT/RFT evaluates the value of parameters such as creatinine, blood urea nitrogen (BUN), and uric acid to diagnose inflammation, infection, or damage and detect kidney disease. In addition, people with diabetes, hypertension, heart disease, and a family history of kidney disease must undergo KFT/RFT regularly to check for any kidney damage.

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Serum Creatinine

The Serum Creatinine test measures the level of creatinine in the blood. Creatinine is a byproduct of muscles’ wear and tear during energy production. The kidneys remove it from the body by filtering it from the blood and releasing it into the urine. Therefore, blood creatinine levels indicate how well the kidneys are functioning in filtering and removing waste products from the blood. Generally, higher creatinine levels in the blood may indicate reduced kidney function, while lower levels may suggest decreased muscle mass.

Know more about Serum Creatinine

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Uric Acid

An Uric Acid test determines the level of uric acid in your body. Uric acid is a nitrogenous compound produced by the metabolic breakdown of purine. Purines are present as nitrogenous bases in the DNA and are also found in food like red meat and seafood.

Most uric acid dissolves in the blood and goes into your kidneys. From there, it passes through your body via the urine. Decreased elimination of uric acid is often a result of impaired kidney function due to kidney disease. In many cases, the exact cause of excess uric acid is unknown. Doctors seldom need to test for low levels of uric acid.

Know more about Uric Acid

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Blood Urea Nitrogen (BUN)

A Blood Urea Nitrogen (BUN) test measures the levels of urea nitrogen in the blood. Blood urea is a waste product that is formed in the liver when you eat food and the protein is metabolized into amino acids. This process leads to the production of ammonia that is further converted into urea. Both ammonia and urea are nitrogenous compounds. Your liver releases urea into the blood which is then carried out to the kidneys. In the kidneys, urea is filtered from the blood and flushed out of the body via urine. This is a continuous process, so a small amount of urea nitrogen always remains in the blood.

In the case of a kidney or liver disease, there is a change in the amount of urea present in the blood. If your liver produces urea in an increased amount or if there is any problem in kidney functioning, there might be difficulty in filtering out the waste products from the blood, which can result in increased urea levels in the blood.

Know more about Blood Urea Nitrogen (BUN)

Interpreting KFT (Kidney Function Test) results


These are simple blood tests that can identify some problems with your kidneys. 

Abnormal or raised levels than normal may indicate some kidney defect. Abnormal KFT/RFT may also suggest that your underlying conditions, like diabetes or high blood pressure, affect the kidney.

Note that sometimes, increased levels of the KFT/RFT parameters may not necessarily be due to health disorders. For example, increased creatinine levels can occur due to heavy exercise, consumption of cooked meat, or taking protein supplements. Thus, these parameters are also considered while interpreting the tests. Further tests are performed to confirm any health disorders.

Answers to Patient Concerns & Frequently Asked Questions (FAQs) about KFT (Kidney Function Test)

Frequently Asked Questions about KFT (Kidney Function Test)

Q. What is the KFT (Kidney Function Test)?

The KFT (Kidney Function Test) is a diagnostic test to check how efficiently your kidneys work.

Q. Why is a KFT (Kidney Function Test) performed?

The KFT (Kidney Function Test) is performed to check the working efficiency of the kidneys, diagnose any kidney disease or damage, and monitor the treatment response in patients with renal conditions.

Q. Is fasting required for the KFT?

No, you do not need to fast before the KFT. You can eat and drink according to your daily routine.

Q. Is there any risk associated with the KFT?

KFT is a simple blood test with no potential health risk. However, you can feel slight pain or bruise at the site of the needle prick.

Q. What tests are done to evaluate my kidney function?

A Kidney/Renal Function Test is done to evaluate your kidney function. It includes a series of tests like a creatinine test, BUN (Blood Urea Nitrogen) test, and uric acid test.

Q. What are the common signs and symptoms of kidney problems?

Urinating more or less, back pain, belly pain, muscle cramps, loss of appetite, fatigue, and weakness are some of the common signs and symptoms of kidney problems.

Q. What are the symptoms of kidney stones?

The symptoms of kidney stones include severe, sharp pain in the sides of the stomach and back, below the ribs, pain that radiates to the lower belly or back of your stomach, and pain or burning sensation while urinating.

Q. How can I prevent a urinary tract infection (UTI)?

Drinking plenty of fluids, practicing safer sexual hygiene, consuming vitamin C-rich foods such as oranges, strawberries, tomatoes, and broccoli, and taking probiotics are some ways to help prevent a UTI.

Q. How can I improve my kidney health?

Healthy eating habits, an active lifestyle, limited alcohol intake, and drinking plenty of water to stay hydrated are some of the ways to improve kidney health.

Q. What are the best food choices for healthy kidneys?

Dark green leafy vegetables, sweet potatoes, apples, onions, bell peppers, radishes, and lemon juice are some foods that help keep the kidneys healthy. However, if you are on a restricted diet, please consult your dietitian for a diet chart that may be appropriate for you.

Q. How can I get my KFT (Kidney Function Test) report from Tata 1mg?

The e-report of your KFT (Kidney Function Test) can be found on the Tata 1mg app in downloadable PDF form. This allows you to access your test results at convenience and securely share them with your healthcare provider for further consultation and guidance regarding your kidney health. You can also opt for a hard copy of the reports at a minimal price.
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