Your report arrives with one line flagged: ALP, a little above the range printed beside it. Nothing else looks out of place, and you are left wondering whether this is your liver, your bones or neither.
A slightly high ALP, short for alkaline phosphatase, can come from either: it is made mostly in the liver and bile ducts and in bone, and the other results beside it show which. At Blood London the Liver Function Tests panel puts those results next to your ALP for £72.50 plus the £50 blood draw, back in 1 day, and a doctor can review your report for £75. If you would like to start with the number itself, the ALP blood test costs £39.38 plus the £50 blood draw (£89.38 in total), with results in 1 day at 117a Harley Street.
Where ALP comes from, and what answers each source
A single ALP figure carries no label saying which tissue made it. Doctors work that out from what it travels with.
| Source of ALP | What it usually travels with | Blood London test that answers it |
|---|---|---|
| Liver and bile ducts | Gamma GT, bilirubin, ALT and AST | Liver Function Tests, £72.50, 1 day, or Gamma GT alone, £36.25, 1 day |
| Bone | Calcium and phosphate | Bone Screen, £73.75, 1 day |
| Growth and pregnancy | Nothing unusual; ALP is normally higher in teenagers and during pregnancy | Usually none needed; a doctor reads it against your age and stage |
| Unclear after the above | Needs the ALP itself to be split by tissue | ALP isoenzymes, £157.50, 5 days |
Each price is plus the £50 draw, which is charged once per visit however many tests you add.
The bile duct clue
Bile ducts are the small channels that carry bile out of the liver. When bile flow slows, ALP and Gamma GT tend to rise together. That pairing points a doctor towards the liver or bile ducts, while a raised ALP with an ordinary Gamma GT looks more like bone. For the full picture of the other markers, our guide to liver function test results goes through each one.
The bone clue
Bone constantly renews itself, and cells that build new bone release ALP as they work. A healing fracture, a growing teenager and some bone conditions all raise it for that reason. Calcium and phosphate sit alongside it as the minerals bone is made from, so a doctor checking bone looks at all three together. The Bone Screen covers that set, and it includes a 24-hour urine collection with the blood test.
"Everyone worries about a slightly high ALP. On its own it doesn't tell me much. I want the other liver results next to it, and I'll ask whether you've broken a bone recently."
Dr Mohammad Bakhtiar, Clinical Lead, GMC 4694470
What the extra £33.12 buys
ALP alone is £39.38. The Liver Function Tests panel is £72.50 and includes ALP with seven other markers: ALT, AST, GGT, bilirubin, total protein, albumin and globulin. That is £33.12 more, and it buys the context a doctor reads before saying anything about your ALP.
The panel also costs less than building it up piece by piece: ALP (£39.38) and Gamma GT (£36.25) bought separately come to £75.63, which is £3.13 more than the full panel. If you are checking a bone question, start with the Bone Screen instead.
The test that separates the two
Sometimes the other results are all unremarkable and ALP is still high. ALP isoenzymes is the test built for that. It splits your ALP into its tissue sources, so bone and liver origin are reported separately. It costs £157.50, takes 5 days, and sits with the other private blood tests in London we offer for follow-up questions like this.
Seeing a doctor about the result
Walk in any day of the week at 117a Harley Street. Weekdays we are open 09:00 to 18:00 and at weekends 10:00 to 14:00. Add a doctor review of your report for £75 and a clinician will go through your ALP with you alongside everything else on it. If the review points to further tests, our sister clinic Medical Express Clinic can arrange them.
Bring any recent history, such as a fracture, a pregnancy or a new medicine, because it changes how the figure reads.
Frequently asked questions
Is a slightly high ALP common?
Yes. Growth, pregnancy and healing bone all raise it without a problem in the liver, which is why a doctor looks at your age and history before the number.
Do I need to fast for the Liver Function Tests panel?
No fasting is needed for that panel. If your own doctor has given you specific instructions, follow those.
How soon will I have my result?
ALP alone and the Liver Function Tests panel are back in 1 day, and ALP isoenzymes take 5 days. The clock starts when your sample reaches the lab, which is the day it is taken.
Can I add a doctor review to any of these tests?
Yes. The doctor review is £75 and can be added to a test when you book.
Book a walk-in blood test at Harley Street, or read how walk-in appointments work first.