Insight into your kidney function.
Creatinine and eGFR together give insight into the filtration function of your kidneys. The eGFR is calculated based on your creatinine level, among other factors.
Also known as: creatinine, eGFR, kidney function
Personal assessment by our BIG-registered Bloodworks® doctors
By the Bloodworks editorial team
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Background
What are creatinine and eGFR?
Creatinine is a waste product that is continuously produced by the breakdown of creatine in your muscles. Your kidneys filter creatinine out of the blood and excrete it in the urine. Because production is fairly constant, the amount of creatinine in your blood says something about how well the kidneys filter: if the kidneys filter less, the creatinine level rises.
The eGFR is not a separate measurement but a calculation. The abbreviation stands for estimated Glomerular Filtration Rate, the estimated speed at which your kidneys filter the blood. That estimate is made using your creatinine level combined with factors such as age and sex. The eGFR makes the creatinine level easier to interpret, because muscle mass and age strongly influence creatinine on its own.
In brief
Waste product
Creatinine comes from the breakdown of creatine in muscles
Filtration
The kidneys remove creatinine from your blood
eGFR
Calculated estimate of the filtration rate
Muscle mass counts
High muscle mass can raise the creatinine level
This marker is also included in
Testing several values in a single draw takes one blood collection and gives a more complete picture. The choice is yours.
Common reasons to test
When can insight into your Creatinine + eGFR be valuable?
Below are some situations in which measuring Creatinine + eGFR can provide insight.
Insight into your kidney function
Creatinine and eGFR are the usual first step in assessing the filtration function of the kidneys.
With high blood pressure or diabetes
High blood pressure and diabetes place a burden on the kidneys over time. Kidney function is therefore monitored more often in these cases.
With long-term medication use
Some medicines are excreted via the kidneys or can place a burden on them. Insight into kidney function is then relevant.
For athletes and strength athletes
High muscle mass and the use of creatine can raise the creatinine level without anything being wrong with the kidneys. The eGFR helps to interpret this.
With kidney problems in the family
If kidney disease runs in your family, people more often choose to have kidney function measured periodically.
Tracking a value over time
For kidney function the trend is often more informative than a single measurement. Re-testing makes a change visible.
What your result means
Creatinine too high or too low: what does your result mean?
Creatinine is measured in micromoles per litre (µmol/L), the eGFR is reported in millilitres per minute. The laboratory states the reference values that apply there alongside your result. Important: muscle mass, age, fluid intake and the use of creatine influence the creatinine level.
A low creatinine value
A low creatinine level is usually harmless and is seen more often with low muscle mass, for example at a lower body weight or at an older age. On its own it does not point to a kidney problem. Our doctor provides explanation and context with your result.
A normal value
A creatinine level within the laboratory's reference values, with a matching eGFR, gives a reassuring picture of the filtration function at this moment. It remains a snapshot: for kidney function, the development over time is often more informative than a single measurement.
An elevated creatinine value
An elevated creatinine level, or a reduced eGFR, may point to reduced filtration function of the kidneys. There are also harmless explanations, such as high muscle mass, the use of creatine supplements, a heavy training session shortly before the draw, or dehydration. A single measurement is therefore not a diagnosis. Our doctor explains what your value means and whether a repeat test or follow-up via your GP is customary.
How we interpret your result
Our doctors interpret your creatinine and eGFR against the laboratory's reference values and your personal context, such as age, muscle mass, lifestyle, medication use and any known conditions.
Related tests
Often combined with Creatinine + eGFR.
A single marker gives one perspective. For a broader picture you can combine Creatinine + eGFR with a theme package or related markers.
+ €29 blood draw fee per orderFree from €225
Frequently asked questions
Everything you want to know
Do I need to fast for a creatinine test?
No, you do not need to fast for creatinine and eGFR. Do drink water normally, as dehydration can influence the value.
What is the difference between creatinine and eGFR?
Creatinine is the waste product measured in your blood. The eGFR is not a separate measurement but a calculation based on your creatinine level, age and sex, among other factors. The eGFR estimates how quickly your kidneys filter the blood and thereby makes the creatinine level easier to interpret.
Does creatine as a supplement affect my result?
Yes. Creatine supplements and high muscle mass can raise the creatinine level without anything being wrong with your kidneys. Please mention creatine use with your result, so the doctor can take it into account.
Does exercise affect the measurement?
A heavy training session shortly before the blood draw can temporarily raise the creatinine level. For a well comparable measurement it is customary to avoid very intensive strength training the day before.
Can a single elevated value mean kidney disease?
No. A single measurement is not a diagnosis. Dehydration, muscle mass, creatine use and a recent heavy training session can temporarily raise the value. For kidney function, the trend over time is usually more important than a single value.
How often should I have my kidney function measured?
A single measurement is enough for initial insight. With high blood pressure, diabetes, long-term medication use or a previously abnormal value, periodic re-testing is customary. Your doctor will advise on this.
What do I do with my result?
You receive a PDF report with your values and personal explanation. What you do with it, such as discussing it with your GP, remains entirely your choice.
Which abbreviation stands for kidney function in a blood test?
In a blood test result you usually recognise kidney function by creatinine, sometimes shortened to creat, and by eGFR. eGFR stands for estimated Glomerular Filtration Rate, the estimated speed at which your kidneys filter the blood. Urea is sometimes listed alongside it, a waste product from protein metabolism. The laboratory states the reference values that apply there alongside each determination.
Which blood values say something about my kidneys?
Creatinine and the eGFR calculated from it are the usual first step in assessing the filtering function of the kidneys. Urea is often measured alongside them, but it is strongly influenced by your diet and fluid balance. A broader kidney test adds determinations such as uric acid, sodium and potassium. Our doctor always assesses the values in context with your personal situation.
Is it creatinine or kreatinine?
Both spellings refer to the same substance. Laboratories and doctors usually write creatinine, while kreatinine is the form you see more often in everyday Dutch. Do not confuse it with creatine, the supplement many athletes use. Creatine can raise the creatinine level, so please mention its use during your intake.
In the Health Guide
Read more about this value
Where do you give blood?
You can give blood at collection points across the Netherlands, usually without an appointment.
Find a collection point near you or read how a blood draw works.
Ready for insight into your kidney function?
You receive your creatinine and eGFR including personal explanation from a doctor, typically within 2 working days. No referral required.
Order Creatinine + eGFR →Want to test multiple markers at once?
Combine Creatinine + eGFR with other markers via Bloodworks Select. The blood draw and collection fee is charged once per order, and is waived from €225.
45,-
+ €29 blood draw fee+ €29 blood draw fee per order