Parathyroid Hormone (Active, Intact) - Mass Concentration
This test measures the active, intact form of parathyroid hormone (PTH) in your blood. PTH is a hormone that helps regulate calcium levels in your body.
["This test helps diagnose and monitor conditions affecting calcium balance, including hypoparathyroidism or hyperparathyroidism."]
Key facts at a glance
- LOINC
- 2733-4
- Short code
- PTH-N SerPl-mCnc
- Synonyms
- PTH-N SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- 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 This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like muscle weakness, bone pain, or abnormal calcium levels. It may also be used to check for conditions such as hypoparathyroidism (low PTH), hyperparathyroidism (high PTH), or kidney disease that affects calcium metabolism.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test, but always follow your provider’s instructions. Bring any medications you’re taking, as some may affect results.
What Happens During the Test
A healthcare professional will draw blood from a vein in your arm. The blood sample will be sent to a lab for analysis using a sensitive immunoassay method to measure intact PTH levels.
What the Results Mean
Results help determine whether your PTH levels are too high or too low, which can guide treatment decisions. Your provider will interpret results in relation to your symptoms and medical history.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Abnormal PTH levels can indicate underlying conditions like hypoparathyroidism (low PTH), which may cause muscle cramps, numbness, or seizures. High PTH levels (hyperparathyroidism) can lead to bone weakness, kidney stones, or fatigue. Monitoring this test is critical for managing these disorders.
Short name
Active PTH (Serum)
Frequently asked questions
How often should I get this test?
Can diet affect PTH test results?
What if I’m on medication for calcium or vitamin D?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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