Alkaline phosphatase (ALP) blood test in Chiswick

What the test measures

Alkaline phosphatase is an enzyme found in several tissues, mainly the liver, the bile ducts and bone, with smaller amounts from the gut and, in pregnancy, the placenta. The total ALP measured in the blood is a mix of these sources. A raised level can come from a problem with the flow of bile, or from increased activity in bone as it is broken down and rebuilt.

Because of this, ALP is usually interpreted alongside other markers. If GGT (another liver enzyme) is also raised, the liver or bile ducts are the more likely source, while a raised ALP with a normal GGT points more towards bone. Levels are naturally higher in children and teenagers who are still growing, and during pregnancy. The price includes the blood sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a review of your result with an Omnia practitioner and a GP feedback report on request.

Who it is for

• You want to check your liver and bile duct health, for example if you drink alcohol or have gallstones.
• You have bone pain, or a condition that affects bone, such as low vitamin D.
• You are taking a medicine your prescriber has asked you to monitor for liver effects.
• Your GP found a raised ALP before and you would like to see whether it has changed.
• You have itchy skin or yellowing of the eyes and your GP has suggested a liver check.

Understanding your result

Your report shows your ALP result with the laboratory reference range. A mildly raised ALP is quite common and may relate to bone healing after a fracture, low vitamin D, some medicines or recent pregnancy. Higher or rising levels may point to a blockage or inflammation in the bile ducts, or to a bone condition such as Paget's disease, and usually need further investigation through your GP.

A low ALP is less common and can be linked to low zinc or magnesium, poor nutrition or rare inherited conditions. An unusual reading opens a conversation; it does not settle a diagnosis.

Preparing for your test

No strict fasting is required, but a fatty meal can slightly raise ALP in some people, so a light meal or fasting overnight gives the clearest result. Tell us about any medicines you take, if you are pregnant, or if you have had a recent fracture.

ALP is part of our Liver Function Check, which includes GGT and other markers that help identify the source of a raised result. If low vitamin D could be relevant, see our vitamin D test. To compare options, see every blood test and price in Chiswick.

Questions

How much is an ALP blood test in Chiswick?

The alkaline phosphatase (ALP) blood test costs £59. This covers your sample at our Chiswick clinic, laboratory analysis, a practitioner review and a GP feedback report if you would like one.

Is a high ALP a liver or bone problem?

It can be either. Comparing ALP with GGT and other liver markers, and sometimes with vitamin D and calcium, helps work out which is more likely.

Why is ALP higher in teenagers?

Bones grow quickly during childhood and adolescence, and the bone-building cells release ALP. Higher levels are normal at these ages.

Should I fast before an ALP test?

Fasting is not essential, though avoiding a heavy fatty meal before the test helps give a clear result. We will confirm any preparation when you book.