Interpret Your Alkaline Phosphatase Results
Enter your ALP value below and get an instant, free AI interpretation — a plain-English explanation checked against WHO/IFCC reference ranges.
Medical Disclaimer
This AI-generated interpretation is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Results may vary based on individual health factors not captured here.
Always consult a qualified healthcare professional before making any health decisions. Read full disclaimer →
Alkaline Phosphatase Normal Ranges
ALP is an enzyme found in the liver (bile ducts), bone, intestine, kidneys, and placenta.
| Age Group | Sex | Reference Range | Unit | Notes |
|---|---|---|---|---|
| Adults (18–64) | All | 44 – 147 | U/L | — |
| Children / Pediatric | All | 100 – 400 | U/L | Physiologically higher during growth spurts |
| All ages | Female | 100 – 500 | U/L | Third trimester of pregnancy (placental ALP) |
Also reported in: IU/L.
Why Doctors Order the Alkaline Phosphatase Test
ALP is the primary marker of cholestatic liver disease (bile duct obstruction, primary biliary cholangitis, primary sclerosing cholangitis). In bone disease, ALP rises due to increased osteoblast activity — useful for monitoring Paget's disease and bone metastases.
How to Enter Your ALP Result
Alkaline Phosphatase can be reported in U/L or IU/L. Choose the unit printed next to your result on the lab report so it is compared with the matching reference range.
Reference ranges for ALP differ by age group, so entering your age gives a more accurate reading.
What a Low or High ALP Can Be Associated With
Below the reference range
- Hypothyroidism
- Pernicious anemia
- Zinc deficiency
- Rare: hypophosphatasia (genetic ALP deficiency)
Above the reference range
- Liver: cholestasis, primary biliary cholangitis, PSC, drug-induced cholestasis, liver metastases
- Bone: Paget's disease, bone fractures healing, bone metastases, hyperparathyroidism, rickets
- Physiological: pregnancy (placental ALP), growth in children and adolescents
- Hyperthyroidism
These are common associations, not a diagnosis. A single result is read alongside your symptoms, history and other tests — discuss it with your doctor.
What Can Change Your ALP Result
Before you read too much into a result, consider whether any of these applied:
- Age and sex (adolescents have physiologically high ALP during bone growth)
- Pregnancy (placental ALP elevates total ALP)
- Eating (intestinal ALP temporarily rises after meals)
- Blood group B and O (higher intestinal ALP)
Preparing for the test: Fasting for 2–4 hours is preferred (eating a fatty meal raises intestinal ALP). A morning specimen is ideal.
Symptoms That Often Prompt ALP Testing
- Jaundice
- Pale stools and dark urine (in cholestasis)
- Itching (pruritus — from bile salt accumulation)
- Bone pain (in bone disease)
- Fatigue
Want the full clinical guide to Alkaline Phosphatase?
Reference ranges, causes, symptoms, preparation, and FAQs.