ALP (Alkaline Phosphatase)

Elevated by liver or bone disease — context determines which.

What it is

ALP is found in the liver, bile ducts, and bone. Elevated ALP can reflect bile duct obstruction, liver disease, or increased bone turnover. Interpreting it alongside GGT and other liver markers helps identify the source.

Why it matters

In oncology, ALP can be elevated due to liver metastases or bone involvement. A significant rise in ALP during treatment warrants investigation. Bone-specific ALP isoforms can distinguish the source if needed.

How to test

Standard liver function panel. If elevated, GGT helps distinguish liver vs. bone origin.

This information is for educational purposes only. Always discuss testing and interpretation of results with your care team.

Optimal range

Adults: 44–147 U/L. Context-dependent — trending matters more than a single value.

How often

Every 3–6 months, or with each oncology panel.