Liver and bone markers
High ALP Levels UK: What a Raised Alkaline Phosphatase Means
Reviewed by a qualified clinician · analysed at UKAS-accredited UK labs (ISO 15189)
Last reviewed September 20265 min read
Every Helvy guide is written by our health editors, then checked by a qualified clinician before it goes live and re-checked as the science moves. We name clinical roles, not individuals, until each reviewer has agreed to be credited publicly. This is wellness guidance to help you understand your own data, not a diagnosis.
QUICK ANSWER
Most UK labs print an adult ALP range of 30 to 130 U/L, so a result above 130 gets flagged. Alkaline phosphatase is an enzyme that comes from your liver and your bones, and a mildly raised figure is as often bone or low vitamin D as it is the liver. A second enzyme, GGT, is what separates the two. If your result went the other way, see what an ALP under 30 means.
Not sure which markers you need? Build your test →Your ALP came back at 148. The report has flagged it. Everything you find online mentions the liver, and you have spent the evening wondering how worried to be.
Here is the part most search results bury. ALP is not only a liver enzyme. It is made in your bones too, and in the placenta during pregnancy. A raised figure on its own does not say which of those it came from.
1. What counts as a high ALP?
Adults in the UK share one range, and the two labs below agree on it. That is unusual. Many blood markers differ from lab to lab.
| Lab | Adult range |
|---|---|
| Gloucestershire Hospitals | 30 to 130 U/L, over 18 |
| South Tees Hospitals | 30 to 130 U/L, over 16 |
So a 148 is above the line at Gloucestershire and above it at South Tees too. What that does not tell you is how far above matters. A figure a little over the top of the range and a figure three times it are different situations entirely.
Age changes the picture completely. Gloucestershire prints 130 to 340 U/L as normal for a 10 to 14 year old, because growing bone makes a lot of ALP. Our ALP levels by age chart has the full set of bands.
2. Is a high ALP the liver or the bones?
This is the question that actually decides what happens next, and there is a standard way to answer it. You measure a second enzyme called GGT.
GGT comes from the liver and the bile ducts, which are the small tubes that carry bile out of the liver. It does not come from bone. NHS guidance for clinicians in Bristol, North Somerset and South Gloucestershire puts it like this:
“When ALP is elevated in isolation, the measurement of γ-glutamyltransferase (GGT) can indicate whether the ALP is of hepatic or non-hepatic origin.”
Remedy, BNSSG Integrated Care Board
In plain terms: hepatic means liver. If your GGT is up alongside your ALP, the liver is the likely source. If your GGT is normal, the same guidance says liver disease is unlikely and other causes should be considered. Bone is the usual next place to look.
3. What are the ordinary reasons ALP runs high?
Plenty of them are dull, which is the reassuring bit. The BNSSG guidance notes that for a raised ALP with no other abnormal results, the most likely cause is vitamin D deficiency, or the normal rise children get while growing.
- Low vitamin D. ALP can rise early, before calcium and phosphate move at all.
- Pregnancy. The placenta makes its own ALP.
- Growth. Children and teenagers run far higher and it is normal.
- A healing fracture. Bone repair lifts the bone form of the enzyme.
- Some medicines. Anticonvulsants are one group worth mentioning to whoever reads your result.
The pregnancy point is worth stating plainly. Gloucestershire says high ALP levels occur in pregnancy because of placental production, and that the normal reference ranges do not then apply. South Tees puts the third trimester at roughly three times the usual range. A flagged ALP in pregnancy is often just pregnancy.
Because low vitamin D is the common answer, a vitamin D test is frequently the cheapest useful next step. Our guide to vitamin D deficiency in the UK covers how common it gets over winter.
Where the rest of the liver panel is untouched, the reading narrows. Our guide to a high ALP with normal liver function covers the bone-or-liver question and the test that answers it.
4. What does your ALP mean beside your other liver numbers?
Liver blood tests are read as a pattern, not one result at a time. The pattern people look for is which enzyme is furthest out.
| Pattern | What it points to |
|---|---|
| ALP up, ALT normal, GGT normal | Often bone, vitamin D or growth |
| ALP up, GGT up | Liver or bile duct is the likely source |
| ALP well above ALT | A cholestatic pattern, meaning bile flow |
| ALT well above ALP | Points at liver cells rather than bile ducts |
Cholestasis is the word for bile flow being blocked or slowed. Lab Tests Online UK describes that as the usual reason for an ALP far higher than the other enzymes. It is also why ALP turns up on the workup for itching with no rash. Our guide on high ALT levels takes the other half of that pair, and liver function tests explained walks the whole panel.
One more thing that catches people out. Results drift, and a single reading is a snapshot. A repeat a few weeks later tells you more than an evening of reading about the first one.
5. Which blood test includes ALP?
ALP is part of the standard NHS liver function test, and of the bone profile. If a GP has run either, your ALP is on the report.
Helvy measures ALP in the Thyroid & Vital Organs panel. It comes with ALT, albumin, total protein, your kidney markers and your thyroid hormones, so the enzyme is read as part of a set rather than alone. It is a home finger-prick kit, processed by UKAS-accredited UK labs.
One honest limit. That panel does not carry GGT, so it cannot do the liver-or-bone split described above. No Helvy panel measures GGT. If your ALP is raised and you want that question settled, that is a conversation with your GP. What we can measure alongside it is vitamin D, which sits in both General Energy & Wellness and Vitamins & Minerals, and which the NHS guidance above names as the likeliest ordinary cause.
If you are not sure which panel fits, the build-my-test tool walks you through it in about a minute.
READY TO TEST?
See your ALP next to the numbers that explain it
Helvy's home blood tests report ALP with plain-English context, so a figure just over a range never sparks a needless panic. Samples are processed by UKAS-accredited UK labs.
Frequently asked questions
What ALP level is considered high in the UK?
Above 130 U/L for an adult at most UK labs. Gloucestershire Hospitals and South Tees both publish 30 to 130 U/L. Check the range printed on your own report, since it is the one your result was flagged against.
Is an ALP of 150 something to worry about?
It is mildly above the usual adult range and needs reading, not panic. A GGT test tells you whether it came from the liver or somewhere else, and vitamin D is a common ordinary cause.
Can a high ALP be nothing to do with the liver?
Yes, often. ALP is made in bone as well as liver. NHS guidance says that if GGT is normal, liver disease is unlikely and other causes should be considered.
Does vitamin D deficiency raise ALP?
It can. BNSSG guidance names low vitamin D as the most likely cause of a raised ALP found on its own, and notes ALP can rise before calcium and phosphate change.
Why is my ALP high in pregnancy?
The placenta makes ALP of its own. Gloucestershire states that the normal reference ranges do not apply in pregnancy, and South Tees puts the third trimester at about three times the usual range.
Does Helvy test GGT?
No. None of our panels carries GGT. Thyroid & Vital Organs carries ALP and ALT instead. Vitamin D sits in two separate panels, General Energy & Wellness and Vitamins & Minerals. The GGT step is one for your GP.
Should a raised ALP be retested?
Usually, yes. One reading is a snapshot, and a repeat shows whether the figure is settling or holding. Your GP decides the timing and what to add alongside it.