Alkaline Phosphatase (ALP)

None.

• To diagnose bone disorders in which the activity of bone cells is decreased or increased.
• The test may also be performed to diagnose liver disease.

Alkaline phosphatase (ALP) is an enzyme produced in several organs, including the bones, liver, and intestines, and found in the blood of healthy people. Blood concentrations of ALP may rise whenever there is increased activity of bone cells (e.g., during childhood growth periods or after a bone fracture) or as a result of bone disorders, including osteomalacia, bone cancer, and Paget's disease of bone.

You must avoid ingesting food and drink for several hours before the test.

Blood is drawn from a vein in your arm and sent to a laboratory for analysis.

You follow procedures for venipuncture and are free to leave.

• Certain drugs.
• Pregnancy.
• Chronic alcoholism.
• Excessive consumption of vitamin D.
• Occasionally, lung and breast cancer.
• Failure to fast prior to the test, particularly if a fatty meal was consumed.

ALP levels vary depending on the person's age and sex and can be influenced by a number of other factors ranging from an underactive thyroid gland to pernicious anemia. Results must be correlated with the patient's history and symptoms.

It's minimally invasive.

It detects an abnormality but not its cause.

If ALP levels are abnormally high or low, further tests must be performed to detect the underlying abnormality. To determine whether increased ALP is due to bone or liver disease, a test may be ordered in which ALP is exposed to heat. This may not require a second venipuncture if there is sufficient serum stored from the first blood sample.