Parathyroid Hormone (PTH) by Immunoassay, Total
This test measures the total amount of parathyroid hormone (PTH) in your blood. PTH is a hormone produced by your parathyroid glands that helps regulate calcium and phosphate levels in your body.
["Your doctor may order this test to check for conditions affecting calcium balance or bone health."]
Key facts at a glance
- LOINC
- 81565-4
- Short code
- PT Hrt for tiss viability W RNC IV
- Synonyms
- PT Hrt for tiss viability W RNC IV
- 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
- Method
- pt
- 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 Is Done
Your doctor may recommend this test if you have symptoms like bone pain, frequent muscle spasms, or unexplained high or low calcium levels in your blood. It may also be used in monitoring conditions like kidney disease, osteoporosis, or hyperparathyroidism.
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 if your doctor specifies it, but this is not always required for PTH testing. Bring any medications you’re taking to your appointment.
How the Test Is Done
A healthcare provider will draw blood from a vein in your arm using a small needle. You may feel a quick pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.
What the Results Mean
Results are interpreted based on your overall health, symptoms, and medical history. High PTH levels may suggest overactive parathyroid glands, while low levels could indicate conditions like kidney disease or vitamin D deficiency. Your doctor will discuss the results with you.
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.
◆Associated findings1
Short name
Total PTH
Frequently asked questions
What causes abnormal PTH levels?
How often should I get this test?
Can diet or supplements affect PTH levels?
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