Parathyroid Hormone (PTH) by Immunoassay (Serum)
This test measures the level of parathyroid hormone (PTH) in your blood, which helps regulate calcium and bone health.
["PTH levels can indicate bone health and calcium balance issues."]
Key facts at a glance
- LOINC
- 38158-2
- Short code
- PTH-Intact BS SerPl-mCnc
- Synonyms
- PTH-Intact BS 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 Is This Test Done?
Your doctor may order this test if you have symptoms like bone pain, frequent fractures, or unexplained high or low calcium levels. It’s also used to diagnose or monitor conditions like hypoparathyroidism, hyperparathyroidism, or kidney disease that affect calcium metabolism.
What Does the Result Mean?
Results can vary based on your health status and medical history. High PTH levels may suggest overactive parathyroid glands, while low levels could indicate underactive glands or other conditions. Your doctor will interpret the result in the context of your symptoms and other tests.
Common Conditions Monitored
PTH levels are often checked in people with suspected or known parathyroid disorders, kidney disease, or metabolic bone diseases. It may also be used to evaluate calcium imbalances or monitor treatment for conditions like osteoporosis or Paget’s disease.
How Is the Test Done?
A blood sample is taken from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause discomfort. The sample is sent to a lab for analysis using an immunoassay method to measure PTH concentration.
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.
Clinical Significance: PTH plays a critical role in calcium homeostasis. Elevated levels may indicate hyperparathyroidism (excess PTH production), which can lead to weakened bones, kidney stones, or heart issues. Low levels may signal hypoparathyroidism or other endocrine disorders. Regular monitoring helps manage these conditions effectively.
Short name
PTH Serum
Frequently asked questions
What does a ‘normal’ PTH level mean for me?
How long does it take to get my results?
Can I eat or drink before this test?
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