1,25-dihydroxyvitamin D (Calcitriol)
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Alkaline Phosphatase
36.00
The Alkaline Phosphatase (ALP) blood test measures levels of ALP, an enzyme linked to liver and bone activity. It is commonly used to investigate liver disease, bile duct problems and bone disorders.
Turnaround time
Results available 1 day after arrival in lab. Doctor's report sent the day after results available (if required)
Biomarkers count
1
Same-Day Appointments
UKAS Accredited Labs
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Under 18? Patients under 18 can only be seen at GB Medlabs and Clinilabs, Monday to Friday only.
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Details about Alkaline Phosphatase
What is the Alkaline Phosphatase Blood Test?
The Alkaline Phosphatase (ALP) blood test measures the level of alkaline phosphatase, an enzyme found mainly in the liver, bile ducts and bones. Smaller amounts are also present in other tissues such as the intestines and kidneys.
ALP plays an important role in bone formation and bile flow. When these tissues are affected by disease or damage, ALP levels in the blood can rise.
Because ALP is produced by several organs, the test is commonly used to investigate liver conditions, bile duct obstruction and bone disorders, often alongside other blood tests for a clearer clinical picture.
Why do I need an Alkaline Phosphatase Blood Test?
An ALP blood test may be recommended when symptoms or other blood test results suggest problems with the liver, bile ducts or bones.
You may benefit from this test if you have:
- Abnormal liver function test results
- Persistent fatigue
- Yellowing of the skin or eyes (jaundice)
- Abdominal discomfort
- Bone pain or bone tenderness
- Unexplained fractures
- Vitamin D deficiency
- Symptoms of liver or gallbladder disease
- Monitoring of bone disorders
- Follow-up of known liver conditions
The test helps identify whether the liver, bile ducts or bones may be contributing to symptoms.
Benefits of the Alkaline Phosphatase Blood Test
- Key marker of liver and bile duct health
Elevated ALP can indicate bile flow problems. - Helps assess bone activity
Levels may rise in bone growth or bone disease. - Supports investigation of abnormal liver tests
Often used with other liver markers. - Detects bile duct obstruction
Useful in gallbladder and biliary conditions. - Simple and reliable blood test
Quick sample collection with accurate laboratory analysis. - Useful for monitoring treatment
Helps track liver or bone conditions over time. - Supports diagnosis of metabolic bone disorders
Relevant in conditions affecting bone turnover. - Provides early warning of organ dysfunction
Abnormal results may prompt further investigation.
Step-by-Step – How the Test is Performed
- Book your blood test appointment online
- Attend your chosen UK clinic
- A healthcare professional collects a blood sample
- The procedure takes only a few minutes
- Results are reviewed once available
Optional home blood collection may be available in selected areas.
Your Alkaline Phosphatase Results Explained
Normal ALP Levels
What this means:
- ALP levels are within the laboratory reference range
What it suggests:
Normal liver and bone enzyme activity.
Raised ALP Levels
What this may indicate:
- Liver disease
- Bile duct obstruction
- Gallbladder conditions
- Increased bone activity
Further testing may be required to determine the exact cause.
Low ALP Levels
What this may indicate:
- Nutritional deficiencies
- Certain metabolic conditions
- Rare inherited disorders
Low levels are less common but may require further evaluation if symptoms are present.
How It Works
Simple steps to get your results
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Book Online
Choose your test online and book in seconds. Select your preferred clinic location or home visit option.
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Visit or Test at Home
Attend one of our UK or London clinics, arrange a home nurse visit, or use a finger-prick kit where available.
3
Get Your Results
Your sample is analysed by accredited UK laboratories, with secure results delivered directly to you.
Take control of your health with London Blood Tests
WhatsApp UsHow to Prepare for Your Test
Follow these guidelines for accurate results
Sample Timing
Where possible, attend your blood test between 7am and 12pm. Please wait until any short-term illness or infection has fully resolved before testing. Avoid intense exercise for 24–48 hours beforehand, as this can affect certain markers.
Fasting & Hydration
Fasting is not always required, but some tests may recommend it. If fasting is advised, avoid food for 8–12 hours before your appointment and drink water only. Stay well hydrated, as this helps with sample collection and accuracy.
Medications & Supplements
Continue prescribed medications unless advised otherwise by your clinician. Avoid vitamin, mineral, or biotin supplements for at least 24–48 hours before your test, as these can interfere with results. If you are unsure about any medication or supplement, please let us know before your appointment.
Hormones & Menstrual Cycle
For hormone-related tests, timing within your menstrual cycle may be important. If relevant, follow any specific guidance provided on your test page.
If you have any questions or special circumstances, our team is happy to advise before your appointment.
Frequently Asked Questions
It measures the level of alkaline phosphatase, an enzyme linked to liver, bile duct and bone activity.
Fasting is not usually required, unless the test is combined with other blood tests.
Yes. Temporary increases may occur during bone growth, pregnancy or after certain illnesses.
Yes. It is commonly included in liver function panels.
Yes. Conditions affecting bone turnover can increase ALP.
Some medications can influence liver enzymes, including ALP.
Not always. Mild elevations may be temporary or related to non-serious conditions.
Testing frequency depends on symptoms, medical history or monitoring needs.
It helps identify abnormalities but diagnosis may require additional tests.
Further blood tests, imaging or specialist review may be recommended.
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