Parathyroid Hormone (PTH) by Immunoassay (Serum)
This test measures the level of parathyroid hormone (PTH) in your blood. PTH is a hormone produced by your parathyroid glands that helps regulate calcium and phosphorus levels in your body.
["PTH helps maintain healthy bone and nerve function by controlling calcium balance."]
Key facts at a glance
- LOINC
- 14865-0
- Short code
- PTH SerPl-Imp
- Synonyms
- PTH SerPl-Imp
- 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 doctor may recommend this test if you have symptoms like bone pain, frequent fractures, muscle spasms, or abnormal calcium levels. It may also be used to diagnose or monitor conditions such as hypoparathyroidism, hyperparathyroidism, or kidney disease that can affect PTH levels.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for a few hours before the blood draw. Wear comfortable clothing and plan to stay near the testing site for about 15 minutes while the blood is drawn.
What Happens During the Test
A healthcare professional will insert a small needle into a vein in your arm to collect a blood sample. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood will be sent to a lab for analysis.
What the Results Mean
Results help doctors determine if your PTH levels are too high or too low, which can indicate underlying health issues. While reference ranges vary by lab, abnormal results may prompt further testing or medical evaluation.
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
PTH (Serum)
Frequently asked questions
What Are Common Causes of Abnormal Results?
How Often Should I Get This Test?
Can I Eat or Drink Before the 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