What creatinine, urea (BUN) and eGFR are on a kidney function report, the example ranges MedlinePlus prints, the eGFR bands in KDIGO 2024, why one number is not a diagnosis, whether to fast, Egypt's screening initiative, and the questions to ask your doctor.
Kidney function tests are common lab tests used to evaluate how well your kidneys are working. MedlinePlus (Medical Encyclopedia, reviewed 28 October 2024) lists blood urea nitrogen (BUN) and creatinine among them, and an eGFR can be worked out from the creatinine and other details. No single number is normal for everyone, so the range printed on your report, and your doctor, govern.
Ranges differ by age, sex, muscle mass and lab, as the sections below show with their sources. This page sets published tables out in plain words and lists what to ask. It does not read your result, tell you it is normal, or diagnose anything. The figures come from MedlinePlus, the US National Library of Medicine’s health site, and the 2024 KDIGO guideline on chronic kidney disease (CKD) from Kidney Disease: Improving Global Outcomes, an international guideline group.
In short:
- Creatinine and urea are waste products the kidneys remove from the blood (MedlinePlus, 5 December 2023 and 27 October 2024).
- Check the name and unit beside your number before comparing it with any range: MedlinePlus’s example is for BUN (urea nitrogen), so a result labelled “urea” needs the range printed beside it.
- One number is not a diagnosis (MedlinePlus, 5 December 2023; KDIGO 2024).
Last checked: 31 October 2026, on the pages listed under Sources. Guidelines and pages change, so confirm with your doctor.
What is a kidney function test, and what is on my report?
| Marker on the report | What it reflects (MedlinePlus: creatinine 5 Dec 2023, BUN 27 Oct 2024, eGFR 30 Sep 2026) | Units you may see |
|---|---|---|
| Creatinine | A waste product made when you use your muscles; the kidneys filter it out of the blood | mg/dL or µmol/L |
| Urea or BUN (blood urea nitrogen) | A waste product of protein breakdown, removed by the kidneys | mg/dL in MedlinePlus’s example; check your report |
| eGFR (estimated glomerular filtration rate) | An estimate of how well the kidneys filter, worked out from creatinine (or cystatin C) and details such as age and sex | mL/min/1.73 m² (KDIGO 2024) |
MedlinePlus (eGFR page, 30 September 2026) lists diabetes, high blood pressure, heart disease, a family history of kidney disease, diabetes or high blood pressure, being over 60, smoking and obesity as things that may put you at higher risk for kidney disease, and says to ask your provider how often to be tested if a condition raises your risk.
What is the normal range for creatinine?
| Test (MedlinePlus Medical Encyclopedia, review date) | Example printed by MedlinePlus | Units |
|---|---|---|
| Creatinine, men (creatinine blood test, 13 Jul 2025) | 0.7 to 1.3 | mg/dL (62 to 115 µmol/L) |
| Creatinine, women (creatinine blood test, 13 Jul 2025) | 0.5 to 0.95 | mg/dL (44 to 84 µmol/L) |
| BUN (urea nitrogen), “generally” (BUN blood test, 19 May 2025) | 6 to 20 | mg/dL |
Read 31 October 2026. These are examples, not your lab’s range. The range printed on your report, and your doctor, govern.
The encyclopedia says women often have a lower creatinine than men because they often have less muscle mass, and that normal ranges may vary slightly among laboratories. It prints no figure for children. MedlinePlus’s creatinine page (5 December 2023) adds that what is normal for you depends on your muscle, what you eat, your age and how active you are. KDIGO 2024 (Table 8) lists changes in muscle mass, several diets and creatine supplements among the “non-GFR determinants” of serum creatinine: things other than kidney filtering that can move the number.
Urea or BUN: which one is on my report?
The MedlinePlus BUN page (27 October 2024) says the test measures urea nitrogen, and that levels vary with sex and usually rise with age. The example above, from the encyclopedia’s BUN page (19 May 2025), is for BUN only, in mg/dL. If your report says “urea”, use the range and unit printed beside that number rather than the BUN example. This page gives no conversion between the two.
What is eGFR, and what do its numbers mean?
MedlinePlus (30 September 2026) says your eGFR may be reported as a number that shows how much blood your kidneys filter per minute. The two sources word the bands differently:
| eGFR (mL/min/1.73 m²) | KDIGO 2024 category | MedlinePlus (30 Sep 2026) |
|---|---|---|
| 90 or more | G1, normal or high | 90 to 100: probably no kidney disease |
| 60 to 89 | G2, mildly decreased | 60 to 90: may mean early-stage kidney disease |
| 15 to 59 | G3a (45 to 59) mildly to moderately, G3b (30 to 44) moderately to severely, G4 (15 to 29) severely decreased | 15 to 60: may mean kidney disease |
| Below 15 | G5, kidney failure | Below 15: may mean kidney failure |
KDIGO: Kidney International 2024;105(4S):S117–S314, Table 2. The range printed on your report, and your doctor, govern.
KDIGO defines CKD as abnormalities of kidney structure or function, present for a minimum of 3 months, with implications for health. A footnote to its Table 2 says that in the absence of evidence of kidney damage, neither G1 nor G2 fulfils the criteria for CKD. KDIGO also classifies by the amount of albumin in the urine (the albumin-to-creatinine ratio, ACR), and says people at risk for CKD, and people who have it, should be tested with both a urine albumin measurement and an assessment of GFR (Practice Point 1.1.1.1).
What does a number outside the range mean?
- MedlinePlus (5 December 2023) says a single high creatinine test can’t diagnose a specific condition and you will likely need to be retested or have other tests. It also says blood creatinine can stay in the normal range during the early stages of kidney disease, so a result inside the range does not always mean healthy kidneys.
- It lists dehydration, muscle disorders and injuries, intense exercise and a diet high in meat among the things that can raise creatinine, and says a high level does not always mean a kidney problem.
- KDIGO 2024 says tests should be repeated to confirm CKD after a low eGFR or raised ACR is found incidentally (Practice Point 1.1.1.2), and not to assume the disease is chronic from one abnormal eGFR or ACR, which could follow a recent acute kidney injury or acute kidney disease (Practice Point 1.1.3.2).
Whether any of this applies to your result is a question for your doctor.
Do kidney function tests need fasting?
It depends on what else is on the sample. MedlinePlus (5 December 2023) says that if creatinine is measured as part of a basic or comprehensive metabolic panel, you may need to fast for up to 12 hours, and that you may be asked not to eat meat for 24 hours before the test, because meat can temporarily raise creatinine. For BUN it says no special preparation is usually needed, but that you may need to fast if other tests are ordered on the same blood sample (27 October 2024). Your lab’s instruction sheet decides; which blood tests need fasting sets the common ones side by side.
What should I ask my doctor about my kidney function tests?
- Which tests are on my report, in which units, and what range does this lab print?
- Does this result need to be repeated, and when?
- Could dehydration, a meal heavy in meat, hard exercise, my muscle mass or a medicine I take change this number?
- Do I need a urine albumin test, or another test such as cystatin C, with it?
- How often should I be tested, given my own health?
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In Egypt: are kidney function tests part of the presidential screening initiative?
According to a Ministry of Health and Population statement of 7 May 2026, carried on the State Information Service page (updated 9 May 2026), Egypt’s presidential initiative for early detection of chronic disease includes kidney function tests («وظائف الكلى») among its services, alongside blood pressure, sugar tests, blood fats and body mass index. The statement says the initiative runs through 3,601 primary care units in every governorate and targets citizens over 40, plus people from 18 with a medical history or risk factors linked to chronic disease. It describes the services as free, and the page gives the initiative’s inquiry hotline, 15335, which is not an emergency number (read 31 October 2026).
The statement does not say which tests make up “kidney function”. We searched on 31 October 2026 for an Egyptian Ministry page printing creatinine, urea or eGFR ranges and found none, which does not prove none exists. Ask your unit or lab which range it prints.
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Frequently asked questions
What is the normal range for creatinine?
The MedlinePlus Medical Encyclopedia (reviewed 13 July 2025) prints 0.7 to 1.3 mg/dL for men and 0.5 to 0.95 mg/dL for women as examples. The range printed on your report, and your doctor, govern.
Does a kidney function test need fasting?
Sometimes: up to 12 hours when creatinine is part of a metabolic panel, per MedlinePlus (5 December 2023). Follow your lab’s instructions.
What is the difference between creatinine and eGFR?
Creatinine is a waste product measured in the blood. An eGFR is an estimate of kidney filtering worked out from it and other details such as age and sex (MedlinePlus, 5 December 2023 and 30 September 2026).
Medigize is a non-diagnostic navigation tool. This is general information, not medical advice. In an emergency, call an ambulance or go to the nearest emergency department.
Sources
- MedlinePlus Medical Encyclopedia (US National Library of Medicine): Kidney function tests, review date 28 October 2024, read 31 October 2026
- MedlinePlus: Creatinine Test, last updated 5 December 2023, read 31 October 2026
- MedlinePlus Medical Encyclopedia: Creatinine blood test, review date 13 July 2025, read 31 October 2026
- MedlinePlus: BUN (Blood Urea Nitrogen), last updated 27 October 2024, read 31 October 2026
- MedlinePlus Medical Encyclopedia: BUN blood test, review date 19 May 2025, read 31 October 2026
- MedlinePlus: Estimated Glomerular Filtration Rate (eGFR) and GFR Tests, last updated 30 September 2026, read 31 October 2026
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease, Kidney International 2024;105(4S):S117–S314, published March 2024, read 31 October 2026
- Egypt’s State Information Service (SIS): early detection of kidney disease and chronic-disease screening initiative, carrying a Ministry of Health and Population statement of 7 May 2026, page updated 9 May 2026, read 31 October 2026
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