Alkaline Phosphatase

Overview

Alkaline phosphatase (ALP) is a protein found in all body tissues. Tissues with higher amounts of ALP include the liver, bile ducts, and bone.

A blood test can be done to measure the level of ALP. Reasons the test may be done include: to diagnose liver or bone disease, to check, if treatments for those diseases are working, and as part of a routine liver function test.

You should know that abnormally high serum levels of alkaline phosphatase may indicate bone disease, liver disease, or bile duct obstruction.

What Alkaline Phosphatase results mean

Abnormal results may be due to the following conditions:

Higher-than-normal ALP levels:

  • Bone conditions
  • Osteoblastic bone tumors, osteomalacia, a fracture that is healing
  • Liver disease or hepatitis
  • Hyperparathyroidism
  • Leukemia
  • Lymphoma
  • Paget's disease

Lower-than-normal ALP levels

  • Hypophosphatasia
  • Malnutrition
  • Protein deficiency
  • Wilson's disease

Other conditions for which the test may be done:

  • Alcoholic liver disease (hepatitis/cirrhosis)
  • Biliary stricture
  • Gallstones
  • Giant cell (temporal, cranial) arteritis
  • Pancreatitis
  • Renal cell carcinoma