---
title: "What does a high Alkaline Phosphatase mean?"
type: biomarker-interpretation
url: "https://www.test-well.com/biomarkers/alkaline-phosphatase/high"
biomarker: Alkaline Phosphatase
direction: high
reference_range:
  - "age 18+: 40.0 – 129 U/L"
reviewed_at: 2026-09-06
review_status: reviewed
date_published: 2026-09-05
---

# What does a high Alkaline Phosphatase mean?

> Alkaline phosphatase comes from liver (bile ducts) and bone, so a high level points to one or the other. Bile-duct blockage, fatty liver, certain medications and liver infiltration raise the liver form; growth in adolescents, healing fractures, Paget's disease, vitamin D deficiency and bone metastases raise the bone form. Pregnancy raises it normally. GGT tells the two apart — high GGT points to the liver.


## What is the normal range for Alkaline Phosphatase?

- age 18+: 40.0 – 129 U/L

Often reflects bile-flow problems, liver disease, or bone turnover (including normal growth in adolescents).

## What are the common causes of high Alkaline Phosphatase?

1. Bile-duct obstruction or cholestasis (gallstones, primary biliary cholangitis, medications)
2. Fatty liver, alcohol, other liver disease
3. Bone: adolescent growth, healing fractures, Paget's disease, vitamin D deficiency, hyperparathyroidism, bone metastases
4. Pregnancy (third trimester, normal)
5. Some medications and blood type variants after fatty meals

## What symptoms go with high Alkaline Phosphatase?

- Often none
- Itching, jaundice, right-upper abdominal pain (liver/biliary)
- Bone pain (bone causes)

## What do clinicians usually check next?

- GGT — raised confirms a liver source; normal points to bone
- Bilirubin, ALT, AST
- 25-hydroxyvitamin D, calcium, PTH if bone source
- Ultrasound for a liver/biliary source

Follow-up tests at TestWell: [ALT (Alanine Aminotransferase)](https://www.test-well.com/tests/alt) ($18.99), [GGT (Gamma-Glutamyl Transferase)](https://www.test-well.com/tests/ggt) ($19.99), [Calcium](https://www.test-well.com/tests/calcium) ($26.99), [PTH (Parathyroid Hormone)](https://www.test-well.com/tests/parathyroid-hormone-test) ($59.99).

## How do you recheck Alkaline Phosphatase?

| Test or panel | Type | Price | Fasting | Results |
| --- | --- | --- | --- | --- |
| [General Wellness Panel](https://www.test-well.com/tests/general-wellness-panel) | Panel (4 tests) | $89.99 | Yes | 1–3 business days |
| [Kidney Health Panel](https://www.test-well.com/tests/kidney-health-panel) | Panel (4 tests) | $64.99 | Yes | 2–4 business days |
| [Gut Health Panel](https://www.test-well.com/tests/gut-health-panel) | Panel (5 tests) | $129.99 | No | 3–7 business days |
| [Comprehensive Metabolic Panel](https://www.test-well.com/tests/comprehensive-metabolic-panel) | Test | $22.99 | Yes | 1–3 business days |

Plus one $6 lab processing fee per order; physician authorization included.

## Common questions

### High alkaline phosphatase but normal GGT — what does that mean?

Bone is the likely source: growth, a healing fracture, vitamin D deficiency or Paget's disease. Calcium, vitamin D and PTH are the next checks.

## Related

- [Alkaline Phosphatase reference ranges](https://www.test-well.com/biomarkers/alkaline-phosphatase)
- [Glucose reference range](https://www.test-well.com/biomarkers/glucose)
- [Creatinine reference range](https://www.test-well.com/biomarkers/creatinine)
- [eGFR reference range](https://www.test-well.com/biomarkers/egfr)

## Sources

- [Mayo Clinic Labs](https://www.mayocliniclabs.com/test-catalog/overview/8340)

---

Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-09-06. Review policy: https://www.test-well.com/editorial-policy

Canonical page: https://www.test-well.com/biomarkers/alkaline-phosphatase/high
Machine-readable catalog: https://www.test-well.com/api/catalog.json · MCP server: https://www.test-well.com/mcp · Overview for agents: https://www.test-well.com/llms.txt

Prices are cash-pay, in USD, and include physician authorization; every order adds one flat $6 lab processing fee. Educational content is not a diagnosis — discuss results with a clinician.