Kidney Test

Kidney Function Test (KFT / RFT)

Name: KFT Test: Normal Range for Creatinine, Urea & eGFR
Creator: Suman Konda
Published: 2026-07-05

KFT measures waste products in your blood to assess how well your kidneys are filtering. Here's what creatinine, urea and eGFR values mean for you.¹

Written by Suman Konda, Clinical Pharmacist · Based on peer-reviewed sources · Editorial policy · Not medical advice

Last reviewed and updated: 26 September 2026 · How we check our content

Quick answer

A kidney function test measures creatinine (men 0.74-1.35, women 0.59-1.04 mg/dL), urea, uric acid and eGFR. High creatinine means the kidneys are filtering less well, from dehydration, medicines or chronic kidney disease. An eGFR below 60 for three months defines CKD. Diabetes and high blood pressure are the biggest causes; annual testing is recommended with either.

What is a KFT test?

A Kidney Function Test (KFT), also called Renal Function Test (RFT), measures waste products that healthy kidneys should be removing from your blood. When kidneys are damaged or not working well, these waste products build up. KFT is used to diagnose chronic kidney disease (CKD), monitor diabetic or hypertensive kidney damage, and check kidney health before starting certain medications.

Scroll sideways to see the whole diagram

eGFR categories used to stage chronic kidney disease.

What the chart shows. Kidney function is graded by eGFR from G1 at 90 or above down to G5 below 15. An important qualification: the top two grades are not by themselves chronic kidney disease. G1 and G2 only count as kidney disease when there is also evidence of damage, such as albumin in the urine, blood in the urine, or a structural abnormality on imaging, and the finding has persisted for at least three months. An eGFR of 95 with a normal urine test is a normal result, not stage G1. From G3a downwards the reduction in filtration is itself sufficient. Stage is also only half the picture, because the same eGFR carries a materially higher risk of progression when albumin is leaking, which is why an albumin-to-creatinine ratio is measured alongside.

KFT Normal Ranges

Test	Normal Range	Unit
Serum Creatinine: Men	0.74 – 1.35	mg/dL
Serum Creatinine: Women	0.59 – 1.04	mg/dL
Serum Creatinine: Women	0.5 – 1.1	mg/dL
Blood Urea Nitrogen (BUN)	7 – 20	mg/dL
Serum Urea	15 – 45	mg/dL
Uric Acid: Men	3.5 – 7.2	mg/dL
Uric Acid: Women	2.6 – 6.0	mg/dL
eGFR (kidney filtration rate)	Above 90	mL/min/1.73m²
Sodium	136 – 145	mEq/L
Potassium	3.5 – 5.0	mEq/L

Key points

A Kidney Function Test measures waste products the kidneys should be clearing: creatinine, urea, electrolytes and eGFR.
High creatinine means the kidneys are filtering less well; causes include dehydration, CKD, diabetic kidney damage, high blood pressure and certain medicines.
An eGFR below 60 persisting for 3 months or more indicates chronic kidney disease; staging runs from mild decline (60-89) down to kidney failure below 15.
Diabetes and high blood pressure are the two biggest causes of kidney failure worldwide; annual KFT is recommended if you have either.
Early CKD (stages 1-2) has no symptoms but is detectable with KFT and a urine microalbumin test; catching it early can slow or stop progression.
A mildly raised creatinine from dehydration usually normalises after fluids; a persistently high one needs investigation.

What does high creatinine mean?

HIGH Creatinine above normal

High creatinine means your kidneys are not filtering waste efficiently. Common causes include dehydration, chronic kidney disease (CKD), diabetes-related kidney damage (diabetic nephropathy), high blood pressure, or certain medications. Mildly raised creatinine with dehydration usually normalises after drinking water. Persistently high creatinine needs investigation.

What does low eGFR mean?

LOW eGFR below 60

eGFR (estimated Glomerular Filtration Rate) shows how much blood your kidneys filter per minute. Below 60 for 3+ months indicates Chronic Kidney Disease (CKD). The lower the eGFR, the more severe the kidney damage: eGFR 30–59 = moderate CKD; eGFR 15–29 = severe; below 15 = kidney failure requiring dialysis or transplant. This staging follows the international KDIGO classification, which combines eGFR category with the degree of albuminuria (protein in the urine) to estimate overall kidney risk, since two people with the same eGFR can have very different outlooks depending on their albuminuria level.³

What does high uric acid mean?

HIGH Uric Acid above normal

High uric acid (hyperuricaemia) causes gout: painful swollen joints, especially the big toe. It also increases risk of kidney stones. Common triggers include high-purine foods (red meat, shellfish, offal), excess alcohol, dehydration and obesity. Low-purine diet and medication can control it.

Diabetes, BP and kidneys

Diabetes and high blood pressure are the two biggest causes of kidney failure worldwide. If you have either condition, KFT should be done at least once a year. Early kidney damage (Stage 1–2 CKD) has no symptoms but can be detected by KFT and urine microalbumin test. Catching it early can stop or slow progression.

What kidney function tests measure

Kidney function tests assess how well your kidneys filter waste from the blood. Creatinine, a waste product from muscles, is the core measurement, and from it the laboratory calculates the eGFR (estimated glomerular filtration rate): the best single indicator of kidney function. Urea and electrolytes such as sodium and potassium are usually reported too.

An eGFR above 90 is generally normal, while a value persistently below 60 for more than three months indicates chronic kidney disease, graded in stages by how low it falls.

Why the urine test matters too

Blood tests alone can miss early kidney damage. The urine albumin-to-creatinine ratio (ACR) detects small amounts of protein leaking into the urine, often the first sign of damage, appearing before eGFR declines. This is especially important in people with diabetes or high blood pressure, the two leading causes of kidney disease. A meta-analysis of over 105,000 people found that death risk stayed flat across eGFR 75–105 (a "normal" blood result) but rose steadily with higher ACR at every eGFR level, with no safe threshold, which is why ACR can flag risk that a normal creatinine result alone would miss.²

Combining blood and urine tests therefore gives a much earlier and more complete picture of kidney health.

What affects kidney results

Creatinine and eGFR can be influenced by muscle mass, dehydration, a very high-protein meal and certain medicines, so a single abnormal result is often repeated. Because eGFR is an estimate, trends over time are more meaningful than one reading.

Protecting the kidneys centres on controlling blood pressure and diabetes, staying hydrated, and reviewing medicines that can affect the kidneys, such as some painkillers.

KFT myths vs facts

Kidney tests are among the most anxiety-provoking numbers in medicine. Here is what the evidence actually says:

MYTH A creatinine of 1.3 is fine if eGFR looks okay.

Fact: Creatinine and eGFR are the same information expressed differently — eGFR is calculated from creatinine, age and sex. If they seem to disagree, one is being misread; creatinine must be judged against muscle mass, age and the trend.

MYTH Drinking more water improves your kidney results.

Fact: Hydration affects the numbers slightly, but no amount of water reverses kidney damage — and overhydration before a test can dilute values into false reassurance. Kidneys are assessed by trend, not by one well-hydrated morning.

MYTH One abnormal KFT means kidney failure.

Fact: A single abnormal value has many transient causes — dehydration, recent illness, certain medicines, a heavy meat meal before creatinine. Kidney assessment is about persistence: abnormal values are repeated before any label.

MYTH Blood pressure medicines damage the kidneys.

Fact: Most protect them — controlling blood pressure is among the best-proven ways to slow kidney decline. Some (like ACE inhibitors) cause a small expected creatinine rise when started, which doctors anticipate; stopping them over that rise does more harm.

MYTH Protein in urine is always serious.

Fact: Persistent proteinuria matters, but transient protein appears after exercise, fever and stress. The pattern — repeat testing, quantification — decides, not a single dipstick.

Your KFT result: what to do next

Got your report and wondering what it means for you? Find the branch that matches your situation — every path ends with your doctor, because kidneys are judged by trend, never by one value:

If your result is…	Sensible next step	Talk to your doctor when…
Creatinine mildly raised, first time	Consider hydration, recent illness, medicines, meat meal — repeat after addressing these.	it stays raised on repeat; persistence is what counts.
eGFR reduced	Read with age — eGFR drifts down with age; the trend and the urine findings matter more than one number.	promptly if the drop is large or protein is present.
Protein in urine	Repeat — transient causes are common; persistent proteinuria is quantified.	it persists; that's the finding that changes management.
Normal KFT but diabetes/hypertension	Damage can precede blood-test changes — urine albumin and regular monitoring continue.	at your scheduled reviews; normal today isn't a discharge.

KFT test price in India

In India, the KFT test typically costs &rupee;500–&rupee;1,000, though prices vary by city and lab. It is one of the commonest panels ordered — often alongside urine routine, which adds the proteinuria half of kidney assessment. Where possible, choose a NABL-accredited lab, and remember the range printed on your own report is the one that counts.

Frequently Asked Questions

Do I need to fast for a kidney function test?

No fasting is needed, though avoiding a very large protein meal and vigorous exercise beforehand helps give a representative creatinine result.

What is eGFR?

eGFR estimates how much blood your kidneys filter each minute. Above 90 is normal; below 60 for over three months indicates chronic kidney disease.

Can kidney damage exist with normal blood tests?

Yes. Early damage often shows first as protein in the urine, which is why the urine ACR test matters alongside blood tests.

Is a single abnormal result serious?

Not necessarily: dehydration, diet, muscle mass and medicines can affect results, so abnormal readings are usually repeated to confirm a genuine trend.

My creatinine is 1.3 but my eGFR looks fine. Which one matters?

Both, read together. Creatinine alone doesn't account for age, sex or muscle mass — a muscular young man can sit at 1.3 with perfectly healthy kidneys. eGFR adjusts for those factors, so doctors lean on it, alongside urine tests, for the real picture.

Can drinking more water improve my kidney test results?

Dehydration does raise creatinine temporarily, so steady normal hydration gives the most accurate reading. But water doesn't treat kidney disease — if the numbers stay high when well hydrated, the kidneys need medical attention, not more water.

Is protein in my urine serious?

Persistent albumin in the urine is one of the earliest signals of kidney damage, and it can appear while creatinine still looks normal — especially in diabetes and hypertension. A one-off trace may mean little, but a repeated positive needs follow-up with your doctor.

Do blood pressure medicines affect kidney test results?

Some, particularly ACE inhibitors and ARBs, can nudge creatinine up a little after starting — which is exactly why doctors recheck kidney function a few weeks in. Never stop them because of a lab value; the interpretation and any change belong to your doctor.

How much does the KFT test cost in India?

The KFT test typically costs ₹500–₹1,000 in India, though prices vary by city and lab. Choose a NABL-accredited lab where possible — and remember the reference range printed on your own report is the one that counts. Discuss the result with your doctor.

What is the full form of KFT?

KFT stands for kidney function test.

Pharmacist's practical notes

Medicines are kidney tests' biggest confounder: NSAID painkillers, certain antibiotics and even some supplements move creatinine — and the expected small rise when ACE inhibitors start is anticipated, not alarming. Bring the full medication list to every kidney review; the numbers can't be read without it.

Never stop blood pressure medicines over a creatinine wobble without medical advice — they are usually protecting the kidneys, and stopping them trades a number for the disease. And remember damage can precede blood-test changes: urine albumin testing is the early window, especially in diabetes.

In India

The KFT test typically costs &rupee;500–&rupee;1,000 in India, though prices vary by city and lab.

Where possible, choose a NABL-accredited lab. With diabetes and hypertension so prevalent, periodic kidney monitoring is routine care — not a sign of failure.

References

Sources cited on this page. PubMed links open the original abstract.

Levey AS, Bosch JP, Lewis JB, et al. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Ann Intern Med. 1999;130(6):461–470. PMID 10075613 · doi:10.7326/0003-4819-130-6-199903160-00002
Matsushita K, van der Velde M, Astor BC, et al. Association of estimated glomerular filtration rate and albuminuria with all-cause and cardiovascular mortality in general population cohorts: a collaborative meta-analysis. Lancet. 2010;375(9731):2073–2081. PMID 20483451 · doi:10.1016/S0140-6736(10)60674-5
Inker LA, Astor BC, Fox CH, et al. KDOQI US Commentary on the 2012 KDIGO Clinical Practice Guideline for the Evaluation and Management of CKD. Am J Kidney Dis. 2014;63(5):713–735. PMID 24647050 · doi:10.1053/j.ajkd.2014.01.416

Medical Disclaimer: Creatinine levels vary with muscle mass, age and hydration. A single elevated result does not always mean kidney disease. This information is for educational purposes only. Always consult your nephrologist or physician regarding your kidney function test results.