Normal Values:

The normal value is 20 to 140 IU/L (international units per liter).

Adults have lower levels of ALP than children. Bones that are still growing produce higher levels of ALP. During some growth spurts, levels can be as high as 500 IU/L. For this reason, the test is usually not done in children, and abnormal results refer to adults.

The isoenzyme test results can reveal whether the increase is in "bone" ALP or "liver" ALP.

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

What abnormal results mean:

Higher-than-normal ALP levels:

• Bone diseases or problems, such as healing fractures, certain bone tumors, softening of the bones,hyperparathyroidism, orPaget's disease
• Gallstones, or a blockage in the tubes that carry bile from the liver
• Liver disease or infection of the liver (hepatitis)
• Lymphoma or leukemia

Lower-than-normal levels of ALP:

• Malnutrition
• Protein deficiency
• Wilson's disease

Levels that are only slightly higher than normal may not be a problem unless there are other signs of a disease or medical problem.