An alkaline phosphatase level test with results higher than normal may indicate disease or damage to the liver as a result of hepatitis, cirrhosis, gallstones, liver cancer or a blockage in the bile ducts, states Healthline. Because abnormal results may also indicate a bone disorder, an ALP test alone is not enough to diagnose a liver problem, according to Lab Tests Online.
When other liver tests, such as bilirubin, aspartate aminotransferase and alanine aminotransferase, taken in conjunction with an ALP, also provide higher-than-normal results, this indicates the problem is indeed in the liver and not in the bones, explains Lab Tests Online. Elevated results on a glucose challenge or 5'-nucleotidase test also indicate liver problems.
When the problem with the liver is the result of disease, such as hepatitis, the measured APL levels are typically less than the levels of AST and ALT, states Lab Tests Online. In the event gallstones, scars or cancer is blocking the bile ducts, the measured ALP and bilirubin levels are typically higher than the levels of AST and ALT.
A doctor may order an ALP in patients presenting with specific symptoms such as jaundice, abdominal pain and nausea, informs Healthline. An ALP test determines the amount of alkaline phosphatase, an enzyme that breaks down protein, in the blood. The primary producer of ALP in the body is the liver.
For an adult, the normal range or ALP is between 25 and 100 units per liter of blood, but normal levels vary from individual to individual and depend on certain factors such as age, sex and blood type, explains Healthline. Pregnant women may have higher than normal levels because the placenta produces ALP.