Elevated alkaline phosphatase, or ALP, levels may indicate liver problems, such as cirrhosis, hepatitis, gallstones or liver cancer, or bone problems, such as bone cancer, rickets, osteomalaica or Paget's disease. In rare cases, elevated ALP levels indicate mononucleosis, kidney cancer, heart failure or a blood infection, as stated by Healthline.
Normal ALP levels for an adult are typically anywhere between 25 and 100 units of alkaline phosphatase per liter of blood, and normal levels for a child can reach up to 350 units per liter, as reported by Cigna. Normal ALP levels vary from person to person and lab to lab, and values outside of the standard range do not necessarily indicate a serious health problem. Women experience a natural increase in ALP levels during the third trimester of pregnancy, as the placenta produces alkaline phosphatase. Additionally, ALP levels naturally increase as part of the healing process for bone fractures.
Certain medications can affect ALP test results, including oral diabetes medicines, birth control pills, some antibiotics and aspirin, states Cigna. It is important for patients to inform their doctors of all medications they are currently taking prior to testing, advises Healthline. Excessive alcohol consumption can also skew ALP test results, notes Cigna.