Alkaline phosphotase (ALP)

ALP test can measure a variety of health conditions such as diseases of the liver, pancreatitis, and leukemia.

Alkaline phosphotase (ALP) Overview

Reviewed: April 22, 2014

Alkaline phosphatase (ALP) is a protein found in all body tissues. ALP is found in the liver, bile ducts, kidneys, intestines, and bone. ALP tests measure the level of ALP.

ALP is measured in Units per liter (U/L). The normal ranges for ALP are the following:

  • 10-11 years: 150-470 U/L
  • 12-13 years: 160-500 U/L
  • 14-15 years: 130-530 U/L
  • 16-19 years: 60-270 U/L
  • 20 and older: 40-120 U/L


Blood draw


Fasting 10-12 hours before test is usually required.

What the results mean

Higher than normal ALP levels may be caused by certain bone conditions, liver disease, inflammation of the liver, hyperparathyroidism, leukemia, lymphoma, Paget's disease, or rickets.

Lower than normal ALP levels may be seen with certain conditions such as hypophosphatasia, malnutrition, hypothyroidism, and cystic fibrosis.