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Serum or plasma mass concentration of alkaline phosphatase (ALP)

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of alkaline phosphatase, an enzyme found in the liver, bones, and other tissues. It helps assess conditions affecting these areas.

Quick summary

["ALP helps identify liver or bone disorders by measuring enzyme activity in your blood."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
106044-1
Short code
MRSA Skin Ql Cult
Synonyms
MRSA Skin Ql Cult
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
organism-specific-culture
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your healthcare provider may order an ALP test to check for liver disease, such as hepatitis or bile duct blockage, or to evaluate bone health, including conditions like osteoporosis or bone metastases. It can also be used during pregnancy to monitor liver function or in children to diagnose growth-related bone issues.

Common Conditions Monitored

High ALP levels may suggest liver problems (e.g., bile duct blockage, cirrhosis), bone disorders (e.g., Paget’s disease), or certain cancers. Low levels are less common but could indicate liver disease progression or severe bone demineralization.

Sample Collection and Preparation

This test requires a blood sample drawn from a vein, usually in your arm. The blood is separated into serum (liquid part after clotting) or plasma (liquid part after anticoagulant use) for testing. Avoid eating or drinking for 2–4 hours before the test if instructed.

Test Method and Results

The test uses an enzymatic method to measure ALP activity. Results are reported in units per liter (U/L) or milliliters per liter (mU/L), but exact ranges vary by lab and individual health. Your provider will interpret results in the context of your overall health.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

ALP Level

Frequently asked questions

How long does it take to get my results?
Results are typically available within 1–3 business days, depending on your lab and healthcare provider’s workflow. Follow-up may be needed if results are abnormal.
Can I eat or drink before this test?
Check with your provider for specific instructions, but generally, avoid food/drink for 2–4 hours before blood collection to ensure accurate results.
What are typical reference ranges?
Reference ranges vary by lab and age. For adults, they often range from 44 to 148 U/L (serum) or 36 to 104 U/L (plasma), but your provider will use lab-specific values tailored to your health.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy