What is alkaline phosphatase (ALP) and what does it mean for an HPP diagnosis?

Understanding alkaline phosphatase (ALP).

ALP is an enzyme that is essential for the process of building strong bones and teeth. People with hypophosphatasia (HPP) have persistently low ALP, which often explains the frequent bone fractures, tooth loss, and chronic pain that many experience throughout their lives.

The connection between
low ALP & HPP.

Persistently low ALP could be the key to an HPP diagnosis. If you’ve been experiencing symptoms of HPP, ask your doctor for a blood test, because…

Persistently low ALP plus one or more HPP symptoms, such as chronic bone pain or frequent fractures, is enough to confirm HPP after your doctor has ruled out other causes of low ALP. This tool is for educational purposes only and does not replace a healthcare professional’s judgment or clinical diagnosis.


Testing for persistently low ALP.

Curious to know what your ALP levels are? Look back at your previous blood tests and prior medical records with your doctor. If alkaline phosphatase levels are persistently low, it may indicate an HPP diagnosis. But remember—if you do receive an HPP diagnosis, support is available.

Support for HPP

Your numbers may help you find long-awaited answers related to your health. Check your ALP levels against age- and sex-adjusted reference intervals (U/L)

Select a sex to see ALP levels.

Female Male

Normal level

90 - 273 U/L

Low level

< 90 U/L

Normal level

134 - 518 U/L

Low level

< 134 U/L

Normal level

156 - 369 U/L

Low level

< 156 U/L

Normal level

141 - 460 U/L

Low level

< 141 U/L

Normal level

62 - 280 U/L

Low level

< 62 U/L

Normal level

54 - 128 U/L

Low level

< 54 U/L

Normal level

48 - 95 U/L

Low level

< 48 U/L

Normal level

40 - 120 U/L

Low level

< 40 U/L



Measured in U/L (Units per Liter)

This tool is not intended for use in the diagnosis of any disease or condition, or for the cure, mitigation, or treatment of any disease or condition. It does not replace a healthcare professional’s judgment or clinical diagnosis.

Adapted from the Canadian Laboratory Initiative on Pediatric Reference Intervals (CALIPER) project (Colantonio et al, 2012). No variation in ALP based on ethnic differences was observed. Reference intervals shown were established on the Abbott ARCHITECT C8000 analyzer.

Check with your doctor for the appropriate age -and sex- adjusted reference range. Low ALP is not conclusive for diagnosis of HPP. Patients should be evaluated for other symptoms of HPP and differential diagnosis should be ruled out.

How is ALP measured?

ALP levels are measured with a blood test called a comprehensive blood panel. It’s important for your doctor to adjust for age and sex in order to produce an accurate reference range.

Do you know your alkaline
phosphatase level?

Enter your age and alkaline phosphatase value from a recently administered blood test to find out more. This tool is for educational purposes and does not replace a healthcare professional’s judgment or clinical diagnosis.



Did you know you can find your ALP levels on a comprehensive blood panel? They can be checked with a simple blood test.

Your ALP Level
Normal ALP


I would say ‘Go to the doctor. Get your ALP checked. Take note of your symptoms, write them down. Take yourself seriously and keep pushing to get help.’”


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