Alkaline Phosphatase High (ALP): Liver vs Bone Causes, GGT Clues, and Next Steps

8/22/2025

Alkaline phosphatase (ALP) can be elevated from the liver/biliary tree or from bone. People often search: "ALP high", "alkaline phosphatase 150", "is ALP high dangerous", "cholestasis vs bone disease". The key step is identifying the source.

First question: liver or bone?

Check GGT (gamma-glutamyl transferase). ALP up + GGT up suggests a hepatobiliary source.
ALP up + GGT normal suggests a bone source (growth, healing fracture, high bone turnover).
Some labs can run ALP isoenzymes to confirm origin.

If liver/bile ducts are suspected (cholestatic pattern)

Symptoms: itch, pale stool, dark urine, jaundice, right-upper-quadrant pain.
Causes include gallstones, biliary stricture, primary biliary cholangitis, primary sclerosing cholangitis, medication-induced cholestasis, pregnancy cholestasis, infiltrative disease.
Next steps (education): review meds/supplements; liver panel (ALT, AST, bilirubin); abdominal ultrasound; autoimmune markers if persistent; consider MRCP depending on clinician judgement.

If bone origin is likely

Physiologic: adolescence growth spurts, late pregnancy, fracture healing.
Pathologic: vitamin D deficiency, hyperparathyroidism, Paget disease, bone metastases (less common).
Next steps (education): check 25-OH vitamin D, calcium, phosphate, PTH; consider bone-focused imaging if red flags.

Red flags (seek urgent care)

Fever with jaundice, rapidly worsening abdominal pain, confusion, or bleeding.
Severe bone pain with weight loss or neurologic symptoms.

FAQs

Can fatty liver raise ALP?

MASLD/NAFLD typically raises ALT/AST more than ALP, but mixed patterns occur, especially with steatohepatitis or coexisting cholestasis.

Does vitamin D deficiency raise ALP?

Yes. Vitamin D deficiency and high bone turnover can elevate ALP from the bone fraction.

Educational use only. Not medical advice, diagnosis, or prescription.

Educational information only — not a diagnosis, treatment, or prescription.