Kidney Function Test (KFT) involves a set of tests that evaluate how well the kidneys perform their critical functions. Healthy kidneys maintain overall health and wellness. Kidneys are bean-shaped organs of the urinary system located in the lower back on either side of the spine. They help eliminate waste products like urea, creatinine, and uric acid while regulating blood pressure, producing red blood cells, and activating vitamin D for bone and muscle health.

The tests measure the most essential parameters of kidney health, including the glomerular filtration rate (GFR), which evaluates the efficiency with which the kidneys filter waste materials from the bloodstream.

KFT blood tests are critical not only for diagnosing kidney diseases but also for monitoring their progression, evaluating treatment efficacy, and identifying complications early. Considering the global prevalence of chronic kidney disease (CKD), regular testing is especially important for individuals at higher risk. Monitoring kidney function is also crucial for individuals diagnosed with chronic diseases such as diabetes or hypertension or when symptoms of potential kidney problems—like blood in urine, difficulty urinating, or frequent urination—are present.

KFTs with electrolytes offered by Orange Health Labs include an evaluation of electrolytes, making it convenient to assess overall kidney health.

In India, the KFT test cost is around ₹700 . This cost involves convenient sample collection from your home within 60 minutes of confirming the booking. Orange Health Labs provides competitive pricing and the convenience of at-home testing. Based on your location and laboratory selected, the pricing may vary. At Orange Health Labs, the KFT blood test cost across different cities is provided below:

To prepare for a KFT, check the following testing pre-requisites:

Pre-requisites: Fasting may not be required for a KFT; however, you should ensure that you follow all the instructions given by the doctor before the test. Hydration is important before testing. Certain foods or beverages might need to be avoided before the test, as per your doctor’s advice.

Precautions Before the Test: Inform your treating doctor about any medications or supplements you are taking, as some may affect the KFT test results . However, do not stop any medications unless explicitly instructed by your doctor.

The Kidney Function test is typically conducted using a blood sample. In some cases, a urine sample may also be required. After booking the KFT with Orange Health Labs, an experienced eMedic will arrive at your doorstep for sample collection. The KFT test procedure steps are as follows:

• Preparation : Our professional eMedic will help you understand the test procedure initially. You will be asked to sit comfortably.

• Site Selection : The eMedic will choose an appropriate vein, typically in the inner elbow area, and clean the skin over it with an antiseptic wipe.

• Needle Insertion : A needle will be inserted in the vein and blood will be drawn. You may experience a mild sting or pinching sensation at this time.

• Blood Collection : The required amount of blood will be collected in a vial.

• Needle Removal : The eMedic will remove the needle and apply pressure at the needle insertion site with a gauze pad to stop any bleeding.

• Bandaging : Lastly, a small bandage will be placed over the puncture site to protect it.

• Urine Collection : The process involves collecting a clean, midstream urine sample in a sterile container provided by the laboratory.

The entire procedure of sample collection typically takes about 10-15 minutes . The results of KFT are usually available within 6 hours after the sample is collected.

KFT blood tests are crucial for evaluating kidney health and detecting potential issues early. They are especially important for individuals at risk of kidney-related problems or experiencing concerning symptoms. A KFT blood test is essential for the following reasons:

• Monitoring chronic conditions : Conditions like diabetes, high blood pressure, and other long-term illnesses can impact kidney function and need to be monitored.

• Identifying symptoms of kidney issues : Signs like blood in the urine (haematuria), painful urination (dysuria), or frequent urination may indicate underlying kidney problems and should be checked.

• Preventing complications : Early detection of kidney dysfunction can help prevent serious complications, such as kidney failure.

• Assessing overall health : Regular KFTs provide valuable insights into electrolyte balance and waste filtration, ensuring optimal kidney performance.

• Evaluating acute conditions : KFTs help diagnose and manage acute kidney injury or other sudden changes in kidney function.

Regular testing supports timely intervention and better management of kidney health.

Kidney Function test is essential for individuals with specific risk factors or symptoms that may indicate kidney problems. Individuals who should consider a KFT are:

• Individuals with chronic illnesses including high blood pressure, diabetes, and heart disease.

• Those with a family history of kidney disease.

• Individuals experiencing symptoms of kidney problems such as fatigue, swelling, and changes in urination.

• Patients on medications that may affect kidney function.

• Individuals who are advised to monitor kidney health regularly.

Certain symptoms and health conditions may impact kidney health and may also lead to potential kidney problems, making it important to get a KFT blood test. These signs may include:

• Persistent swelling in the hands, face, or feet

• Fatigue

• Changes in urination (colour, pain, frequency)

• Shortness of breath

• Persistent lower back pain

• Nausea and vomiting

• Weight loss and reduced appetite

• High blood pressure

• History of diabetes

The table given below summarises the KFT test - interpretation of results:

The key parameters assessed in KFT are stated below:

• Urea/Blood Urea Nitrogen (BUN): Measures the level of urea, a nitrogen-based waste product cleared by the kidneys. Elevated levels may indicate kidney dysfunction, dehydration, liver disease, or gastrointestinal conditions.

• Creatinine : Determines creatinine levels in blood. It is a waste product that is produced as a result of metabolism within muscles. High blood creatinine levels suggest reduced kidney filtration efficiency and impaired kidney function.

• Uric Acid : Tests uric acid levels in blood or urine. High levels are associated with conditions like gout, kidney tubule damage, or certain cancers, while low levels may indicate CKD.

• Estimated Glomerular Filtration Rate: Provides an estimate of kidney filtration efficiency, indicating how well kidneys remove waste from the blood. eGFR is a key parameter for diagnosing and staging kidney diseases.

• Urea-Creatinine Ratio (UCR) : Checks the balance between urea and creatinine in the blood. An elevated UCR may indicate kidney injury, muscle wasting, or critical illness-related weakness.

• Electrolytes : Includes measurements of essential minerals like calcium, potassium, sodium, chloride, and phosphorus. This panel evaluates the body’s mineral balance, as kidneys regulate these levels to maintain homeostasis (balance).

These parameters offer valuable insights into kidney function, helping to diagnose and monitor various kidney-related conditions effectively.

The KFT test normal range can be used as a reference to assess kidney health. Each parameter in the test has a specific range that indicates optimal functioning. When values of the parameters are within their normal range, it typically suggests healthy kidney performance and proper regulation of body fluids and electrolytes. Deviations from the normal range may indicate underlying issues that require further investigation or medical intervention.

Several factors can influence the results of a Kidney Function test. These include medical conditions, medications, and lifestyle elements, all of which can alter kidney function and affect test outcomes. Understanding these factors helps in the accurate interpretation of test results.

Medical Conditions That Can Impact KFT Results

Certain health conditions can directly or indirectly affect kidney function, leading to variations in KFT parameters:

• CKD

• Diabetes and uncontrolled blood sugar levels

• High blood pressure (hypertension)

• Acute kidney injury

• Liver disorders

• Gout or other uric acid-related conditions

Medications That Can Affect KFT Results

Some medications may influence kidney function or test values, either by affecting kidney performance or altering levels of electrolytes and waste products:

• Diuretics

• Nonsteroidal anti-inflammatory drugs (NSAIDs)

• Antibiotics like aminoglycosides

• ACE inhibitors and ARBs

• Chemotherapy drugs

• Immunosuppressants

Other Factors That Can Affect KFT Results

Non-medical elements can also impact KFT results, often related to lifestyle, diet, or physiological conditions:

• Dehydration or overhydration

• A high-protein diet

• Intense physical activity before testing

• Recent use of contrast dyes during imaging tests

• Pregnancy-related changes in kidney function

When to Seek Medical Advice Based on KFT Test Results

After receiving the results of KFTs, prompt consultation with a doctor is essential for abnormal results, especially if they are significantly outside the normal range or accompanied by symptoms.

Consulting a Doctor for High/Abnormal KFT results

• High or Elevated Levels : Elevated levels of urea, creatinine, or other parameters may indicate conditions such as kidney disease, dehydration, or an underlying systemic issue like diabetes or hypertension. Consult a doctor immediately for further investigation.

• Low Levels : Reduced levels of specific parameters, such as eGFR or certain electrolytes, can also suggest impaired kidney function or related complications that require medical attention.

Advantages of Early KFT Testing

Regular Kidney Function testing plays a vital role in safeguarding overall health by evaluating kidney performance and identifying potential issues early. These tests are essential for both preventive care and managing existing conditions. The key benefits of testing are:

• Early Detection of Kidney Issues : Enables timely identification of potential kidney problems, allowing for prompt intervention to prevent further damage.

• Monitoring of Existing Conditions : Helps track kidney function in individuals with chronic conditions like diabetes or hypertension, ensuring effective disease management.

• Prevention of Complications : Supports the prevention of severe complications, such as kidney failure or electrolyte imbalances, through regular monitoring and early action.

• Cost-Effective Screening : Offers an affordable way to assess kidney health regularly, reducing the likelihood of expensive treatments for advanced kidney disease.

Incorporating routine KFTs into routine health checkups can lead to better kidney health outcomes.

The KFT helps detect a wide range of kidney-related and systemic conditions such as:

• CKD

• Acute kidney injury (AKI)

• Glomerulonephritis

• Kidney stones

• Polycystic kidney disease

• Urinary tract infections

Kidney diseases can develop due to various underlying factors, including medical conditions, lifestyle habits, and genetic predispositions. Some of these risk factors include:

• Diabetes

• High blood pressure (hypertension)

• Family history of kidney disease

• Age over 60 years

• Cardiovascular diseases

• Obesity

• Smoking

• Chronic use of medications (such as NSAIDs)

• Chronic urinary tract infections (UTIs)

• Autoimmune diseases (e.g., lupus)

Kidney diseases, especially when left untreated, can lead to a variety of health complications that affect multiple body systems. Some common complications include:

• Anaemia

• Bone weakness

• Gout

• Cardiovascular conditions like high blood pressure, stroke or heart attack

• Nerve damage

• Fluid retention and swelling

• Increased risk of infections

• Kidney failure (end-stage renal disease)

• Bone diseases

Adopting a kidney-friendly lifestyle is essential for protecting kidney health and preventing related complications. Here are some tips to follow:

• Follow a Friendly Diet : Choose fresh fruits, vegetables, whole grains, and lean proteins. Limit sodium, potassium, and phosphorus intake as advised by your doctor.

• Stay Hydrated : Drink adequate water to support kidney function but avoid overhydration.

• Exercise Regularly : Engage in physical activities like walking, swimming, or yoga to maintain a healthy weight and improve circulation.

• Control Blood Pressure and Blood Sugar : Manage hypertension and diabetes through medication, diet, and regular monitoring.

• Avoid Smoking and Excessive Alcohol : Quit smoking and limit alcohol consumption to reduce kidney stress.

• Be Cautious with Medications : Avoid the overuse of painkillers and consult your doctor before taking medications that may impact kidney function.

Managing kidney health requires an understanding of various diagnostic tests. Other tests that can help diagnose kidney-related issues include:

• Urinalysis : A routine test that examines urine for abnormalities such as protein, blood, glucose, or infection, helping to detect early signs of kidney dysfunction.

• Cystatin C Test : Measures cystatin C levels, a more sensitive indicator of kidney function compared to creatinine, useful for detecting subtle changes in glomerular filtration.

• Novel Biomarkers : New biomarkers such as cystatin C, NGAL, KIM-1, and others help detect acute kidney injury, differentiate AKI from CKD, and assess the severity of kidney damage.

• Tubular Function Test : This test assesses the kidneys' ability to maintain acid-base balance and reabsorb water and electrolytes. It includes measuring urine osmolality and electrolyte levels to evaluate renal tubule function and diagnose specific tubular disorders.

The differences between KFTs and other tests are as follows:

• Urinalysis : While KFT analyses blood for kidney function markers, urinalysis focuses on urine for signs of abnormalities such as protein, blood, or infection. It is useful for detecting early-stage kidney issues or infections.

• Cystatin C Test : Unlike KFT, which uses creatinine and BUN, the cystatin C test measures cystatin C levels, offering a more sensitive indication of GFR.

• Novel Biomarkers : Novel biomarkers provide a deeper understanding of kidney injury. They are also helpful in detecting AKI and differentiating it from CKD, often before traditional markers show changes.

• Tubular Function Tests : KFT evaluates overall kidney function, but tubular function tests specifically assess the kidneys' ability to reabsorb electrolytes and maintain fluid balance. These tests can diagnose conditions like Fanconi syndrome or renal tubular acidosis, which aren't typically covered by a standard KFT.

In short, while KFT is essential for general kidney health assessment, tests like urinalysis, cystatin C, novel biomarkers, and tubular function tests provide specific assessment for kidney issues.

KFTs are crucial during pregnancy as they help monitor and assess the impact of kidney health on both maternal and foetal well-being. Pregnancy can affect kidney function, and conditions like preeclampsia, eclampsia, and gestational hypertension may develop or worsen, posing risks to both mother and baby. The early detection of kidney-related issues through KFTs allows for timely interventions to prevent complications such as preterm labour, intrauterine growth restriction, and hypertension. Regular monitoring with KFTs can help manage and mitigate these risks, ensuring better outcomes for both the mother and the foetus.