Alkaline phosphatase, or ALP, is an enzyme naturally produced by your body. As an enzyme, your body requires ALP to trigger specific chemical reactions. However, in larger quantities, ALP can indicate the presence of health problems such as bone or liver disease or cancer. An increase in your ALP levels does not automatically mean you have a specific health problem. Your doctor can run tests to determine the cause of elevated ALP levels in your body.
Purpose of Alkaline Phosphatase
Your body produces ALP to indicate that an event has taken place. However, the production of ALP does not automatically indicate a negative event. For example, your body releases ALP during pregnancy, growth spurts and to repair broken bones. On the other hand, ALP production can also indicate a disorder in your body such as a germ cell tumor, rickets or Paget's disease.
Reason for the Test
Doctors conduct ALP testing to measure the alkaline phosphatase in your serum. The test measures the ALP by combining the serum with substances that will cause a reaction. There are also differences with the ALP released from each of your body's tissues. The process used to test ALP levels in your body will very depending on what part of your body the ALP came from. Each tissue including your bones, intestines, liver produce a slightly different ALP.
No Abnormalities
The results of ALP testing can vary, depending on many factors; doctors often perform multiple to certify results. According to "Guyton and Hall Textbook of Medical Physiology," the standard or normal value for ALP is 20 to 140 IU/L. Your gender and age will also affect this desired range. Since children need ALP for growth, they will typically have higher ALP levels. In fact, children may have ALP levels as high as 500 IU/L during some growth spurts. Doctors typically don't test ALP levels in children because of these variations.
Increased Numbers
Tests that show elevated ALP levels do not necessarily indicate health problems. According to "Harrison's Principles of Internal Medicine," doctors commonly misdiagnosis elevated ALP levels. Further, to rule our misdiagnosis doctors should conduct additional testing to rule out other conditions. Bone and liver disease can increase your ALP levels significantly. Other conditions typically show only slight ALP elevations.
References
- University of Maryland Medical Center; ALP - Overview; David C. Dugdale, III, MD; May 7, 2009
- "Harrison's Principles of Internal Medicine"; Dennis Kasper et al; 2004
- "Guyton and Hall Textbook of Medical Physiology"; John E. Hall; 2010
- "Human Physiology: The Mechanisms of Body Function"; Arthur Vander et al; 1998
