Biomarker . Patient guide
Creatinine Blood Test
What is Creatinine
Creatinine is a waste product from the normal turnover of muscle, cleared almost entirely by the kidneys. Because production is fairly steady, blood creatinine is one of the best routine markers of kidney function and is used to calculate your eGFR.
This biomarker entry is being clinically reviewed by our team. The factual content draws on UK guidance (NICE, NHS, Royal Colleges and the relevant speciality society where cited).
Reference range
Reported in µmol/L. Final reports always carry the issuing laboratory's range, which is what your clinician will interpret against.
| Group | Range | Note |
|---|---|---|
| Adult men | approx. 60 to 110 | µmol/L |
| Adult women | approx. 45 to 90 | µmol/L |
What it is
Creatinine comes from creatine in muscle, so levels relate partly to muscle mass (they run higher in muscular people and lower in older or less muscular people). The kidneys filter it out, so when kidney function falls, creatinine rises. It is the basis of the estimated glomerular filtration rate (eGFR).
Why a clinician would order it
Creatinine is measured to assess and monitor kidney function, before and during medications cleared by the kidneys or that affect them, and as part of a U&E and general health screen. A rising creatinine over time is an important early signal of declining kidney function.
If your level is outside the range
Symptoms of low Creatinine
What low can indicate. Low muscle mass, older age, or pregnancy. A low creatinine is rarely a problem in itself.
Symptoms of high Creatinine
- Often none early on
- With reduced kidney function: tiredness, swelling, reduced urine output, poor appetite
What high can indicate. Reduced kidney function, dehydration, high muscle mass or a very high protein/creatine intake, and certain medications. Because muscle mass affects it, creatinine is best interpreted via the eGFR, which adjusts for age and sex.
Testing tips
No fasting needed. A large meat meal or creatine supplements shortly before testing can transiently raise creatinine. Trends over time matter more than a single value.
Where you can get this tested
Creatinine is included in the following WMG Health panels. Same-day appointments at our Harley Street clinic, with results clinician-reviewed.
Want a specific combination of markers we do not have a panel for? Build a custom panel and our clinicians will design one for you.
Looking to book a test?
Comprehensive private health screening
Full blood screening at 134 Harley Street, London, reviewed by GMC-registered doctors with a written interpretation.
Symptoms often investigated with Creatinine
Creatinine is commonly tested when patients present with the following symptoms. If any of these resonate with you, the linked guides explain what to look for and which test pathway is appropriate.
Sources
UK guidance our clinicians use when interpreting this marker.
This page is general patient information, not personal medical advice. A GMC-registered clinician will review your results and tailor any interpretation to you. See our Editorial Policy for how we write and review content.
Common questions about Creatinine
What is a normal Creatinine range?
Adult men: approx. 60 to 110 (µmol/L). Adult women: approx. 45 to 90 (µmol/L). Always interpret your own results against the laboratory range printed on your report, since assay-specific reference ranges vary.
What does a low Creatinine result mean?
Low muscle mass, older age, or pregnancy. A low creatinine is rarely a problem in itself.
What does a high Creatinine result mean?
Reduced kidney function, dehydration, high muscle mass or a very high protein/creatine intake, and certain medications. Because muscle mass affects it, creatinine is best interpreted via the eGFR, which adjusts for age and sex.
Do I need to fast or prepare for the Creatinine blood test?
No fasting needed. A large meat meal or creatine supplements shortly before testing can transiently raise creatinine. Trends over time matter more than a single value.
Can I order a Creatinine blood test privately in London?
Yes. WMG Health offers Creatinine in several standard panels and as part of a custom panel at our 134 Harley Street clinic. Results are released as each marker is reviewed, and the completion date is set by the slowest marker in your panel. We confirm the expected timeframe at booking. Book a standard panel online, or ask for a custom panel via /contact/ or 020 3239 3378.