ALP Blood Test: definition, levels, causes and symptoms


◉ Why it's done?

The purpose of the ALP blood test is to assess the level of alkaline phosphatase in the blood. Your healthcare provider may order the test as part of a routine exam, for assessing liver function or bone diseases, or to evaluate the impact of certain treatments.

It's important to remember that the alkaline phosphatase test is not a specific diagnostic test on its own. The interpretation of ALP results often requires a comprehensive evaluation and may involve further testing to identify the underlying cause of the abnormal ALP levels.

◉ Preparation and blood sampling

Typically, there is no specific preparation required before undergoing an ALP blood test. However, it is always advisable to follow any instructions provided by your healthcare provider. Here are some general recommendations for blood tests

◉ Normal range of ALP test

The normal range of ALP levels can vary slightly between different laboratories and may depend on factors such as age, sex, and underlying health conditions. However, in general, the normal range for ALP levels in adults is:

It's important to note that ALP levels can naturally fluctuate throughout the day and may be influenced by factors such as pregnancy, growth spurts in children, and certain medications.

◉ High levels of ALP blood test

High levels of alkaline phosphatase (ALP) in the blood (more than 100 U/L for men and more than 130 U/L for women) are known as hyperalkaline phosphatemia or hyperphosphatasemia. Such elevated levels can indicate various medical conditions, including:

Note: It's important to note that elevated ALP levels are not specific to any one condition, so further testing are needed to determine the cause.

◉ Low levels of ALP blood test

Low levels of alkaline phosphatase in the blood (below 25 U/L for both men and women) are known as hypophosphatasemia. Such low levels can indicate certain medical conditions, including:

The ALP blood test is often performed as part of a comprehensive metabolic panel or liver function panel. These panels typically include other tests such as:

The inclusion of these additional tests helps provide a more comprehensive assessment about a person's overall health, liver function, and metabolic status.


Sources

  1. 4- Newsome, P. N., Cramb, R., Davison, S. M., Dillon, J. F., Foulerton, M., Godfrey, E. M.,... & Yeoman, A. (2018). Guidelines on the management of abnormal liver blood tests. Gut, 67(1), 6-19.
  2. Alkaline phosphatase. (n.d.). https://medlineplus.gov/lab-tests/alkaline-phosphatase/
  3. Testing.com. (2022, November 24). Alkaline phosphatase (ALP) test - Testing.com. https://www.testing.com/tests/alkaline-phosphatase-alp/
  4. What is an alkaline phosphatase test? (2017, March 16). WebMD. https://www.webmd.com/digestive-disorders/alkaline_phosphatase_test