The most common causes of elevated alkaline phosphatase levels are liver damage and increased bone cell activity, states Lab Tests Online. Pregnancy can also increase alkaline phosphatase levels.
Healing fractures can cause temporary elevations of alkaline phosphatase, notes Lab Tests Online. Children and adolescents have higher alkaline phosphatase levels than adults because their bones are growing. Some drugs, such as anti-epileptics, can also elevate alkaline phosphatase levels.
If the levels of bilirubin, aspartate aminotransferase or alanine aminotransferase are also high, the increased alkaline phosphatase is likely to be due to liver damage, states Lab Tests Online. If GGT or 5'-nucleotidase levels are high, the elevated alkaline phosphatase is also likely a result of liver disease. If the above markers are not elevated and calcium and phosphorous levels are abnormal, the elevated alkaline phosphatase is likely coming from the bone. A test for alkaline phosphatase isoenzymes may be necessary to distinguish between bone and liver alkaline phosphatase.
Alkaline phosphatase may be elevated due to hepatitis, gallstones or liver cancer. Elevated alkaline phosphatase levels may also be seen in Paget's disease, a disease where bones become deformed, and when cancer has spread to the bones. In these conditions, treatment of the disease may result in lowering of the alkaline phosphatase levels. Hodgkin's lymphoma, congestive heart failure, ulcerative colitis and certain bacterial infections may also cause moderately elevated levels of Lkaline phosphatase, according to Lab Tests Online.