Alkaline phosphatase is an enzyme made in the liver, bone, and the placenta and normally present in high concentrations in growing bone and in bile. It is released into the blood during injury and during normal activities such as bone growth and pregnancy. It is measured in a routine blood test. Abnormally high blood levels of alkaline phosphatase may indicate disease in bone or liver, bile duct obstruction, or certain malignancies. The enzyme is often elevated in chronic myelogenous leukemia. Abnormally low levels of alkaline phosphatase is a genetic condition called hypophosphatasia which results in bone deformities.