Insight into your alkaline phosphatase.
Alkaline phosphatase is an enzyme that comes both from the bile ducts and from bone. The value gives insight into bile drainage, but can also say something about bone metabolism.
Also known as: alkaline phosphatase, ALP, AF, bile ducts, bone
Interpreted by BIG-registered doctors
How Bloodworks works
Order online
Choose your package and preferred location
Receive your lab form
Within 24 hours by email, with appointment planner
Schedule your blood draw
Or choose a walk-in location
Blood draw
Takes just a few minutes
Receive your report
Securely, within a few working days from our physicians
Background
What is alkaline phosphatase?
Alkaline phosphatase (ALP, in Dutch AF) is an enzyme found in several places in the body, mainly in the cells that line the bile ducts and in bone. If the drainage of bile stagnates, or if the bile ducts become irritated, alkaline phosphatase rises in the blood. It therefore complements the liver tests ALT and AST: those point mainly to irritation of the liver cells themselves, while alkaline phosphatase points more towards bile drainage.
Because alkaline phosphatase comes not only from the bile ducts but also from bone, a rise does not always fit the liver. During growth at a young age and during pregnancy, for example, a higher value is usual. To better judge the source of a rise, alkaline phosphatase is often read together with gamma-GT: if gamma-GT is raised too, that points towards the bile ducts; if only alkaline phosphatase is raised, the source may lie in bone.
In brief
Bile ducts and bone
Comes from the bile ducts, but also from bone tissue
Interpret with gamma-GT
Together with gamma-GT the source is easier to judge
Growth and pregnancy
A higher value is then usual
Complements ALT/AST
Points more towards the drainage of bile
Common reasons to test
When can insight into your Alkaline phosphatase be valuable?
Below are some situations in which measuring Alkaline phosphatase can provide insight.
Insight into your bile duct values
Alkaline phosphatase assesses the drainage of bile and complements the liver tests ALT and AST.
With a raised liver value
If your ALT or AST is raised, alkaline phosphatase helps determine whether the bile ducts also play a role.
With questions about bone metabolism
Alkaline phosphatase also comes from bone. The value is therefore sometimes taken into account with questions about bone metabolism.
Together with gamma-GT
The combination with gamma-GT helps the doctor judge whether a rise comes from the bile ducts or elsewhere.
Tracking a value over time
For alkaline phosphatase the development over time is often more informative than a single measurement. Re-testing makes a change visible.
What your result means
How do we read your Alkaline phosphatase level?
Alkaline phosphatase is measured in units per litre (U/L). The laboratory states the reference values that apply there alongside your result. Important: pregnancy, growth in young people and bone metabolism can influence this value.
A low value
A low alkaline phosphatase is uncommon and is sometimes seen with certain nutritional or metabolic factors. Our doctor provides explanation and context with your result.
A normal value
A value within the laboratory's reference values gives a reassuring picture of bile drainage at this moment. It remains a snapshot. The doctor always assesses your value together with your symptoms and your other liver values.
An elevated value
A raised alkaline phosphatase can point to stagnation or irritation of the bile ducts, for example due to gallstones or fatty liver. Because the enzyme also comes from bone, the source may also lie in bone metabolism; during pregnancy or growth a rise is usual. By also looking at your gamma-GT, the doctor can better judge the source. A single measurement is not a diagnosis. Our doctor explains what your value means and whether re-testing or follow-up via your GP is customary.
How we interpret your result
Our doctors interpret your alkaline phosphatase against the laboratory's reference values and your personal context, such as age, pregnancy, medication use and any known conditions.
Related tests
Often combined with Alkaline phosphatase.
A single marker gives one perspective. For a broader picture you can combine Alkaline phosphatase with a theme package or related markers.
Frequently asked questions
Everything you want to know
Do I need to fast for this test?
No, you do not need to fast for alkaline phosphatase. If you are also measuring glucose or cholesterol at the same time, fasting is customary.
What does it mean if only my alkaline phosphatase is raised?
Alkaline phosphatase also comes from bone. If only this value is raised and your gamma-GT is not, the source may lie in bone metabolism rather than in the bile ducts. During pregnancy and in periods of growth a higher value is also usual.
Why is alkaline phosphatase often measured together with gamma-GT?
Gamma-GT comes mainly from the bile ducts and not from bone. If both enzymes are raised, that points towards the bile ducts. If only alkaline phosphatase is raised, the source may lie elsewhere. The combination helps the doctor interpret the origin.
What is the difference between alkaline phosphatase and ALT or AST?
ALT and AST are found mainly in the liver cells and rise with irritation or damage to those cells. Alkaline phosphatase comes mainly from the cells around the bile ducts (and from bone) and points more towards the drainage of bile. They therefore complement each other.
Is a higher value during pregnancy or growth normal?
Yes. During pregnancy and in periods of growth a higher alkaline phosphatase is usual, because the enzyme is also involved in bone metabolism. The doctor takes this into account in the interpretation.
Can a single elevated value already mean a problem?
No. A single measurement is not a diagnosis. The doctor looks at your alkaline phosphatase together with your gamma-GT, your other liver values and your context, and advises whether re-testing or follow-up is useful.
What do I do with my result?
You receive a PDF report with your value and personal explanation. What you do with it, such as discussing it with your GP, remains entirely your choice.
Ready for insight into your alkaline phosphatase?
For €54 you receive your alkaline phosphatase including personal explanation from a doctor, typically within a few working days. No referral required.
Order Alkaline phosphatase for €54 →Want to test multiple markers at once?
Combine Alkaline phosphatase with other markers via Bloodworks Select. Blood draw costs are waived from €225.
54,-
All-in, blood draw included