Parathyroid Hormone (PTH) with Quantitative Immunoassay (Serum)
This test measures your blood levels of parathyroid hormone, a protein that helps regulate calcium and bone health.
["PTH helps balance calcium in your body and supports bone strength."]
Key facts at a glance
- LOINC
- 81564-7
- Short code
- PT Hrt for sarcoidosis W RNC IV
- Synonyms
- PT Hrt for sarcoidosis 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 Might Be Ordered
Your doctor may recommend this test if you have symptoms like bone pain, frequent fractures, or conditions such as sarcoidosis, which can affect calcium metabolism. It may also be used to monitor treatment for conditions like hyperparathyroidism or hypoparathyroidism.
What to Expect Before the Test
No special preparation is needed. You’ll have a small needle inserted into your arm or hand to draw blood. You may feel a slight pinch, but it usually doesn’t cause discomfort. Avoid caffeine or large amounts of calcium-rich foods for 24 hours before the test if instructed by your doctor.
What the Results Mean
Results help doctors diagnose or monitor conditions related to calcium and bone health. High PTH levels may indicate overactive parathyroid glands, while low levels could suggest underactivity or other health issues. Your doctor will discuss these results in the context of your overall health.
Common Conditions This Test Helps Identify
This test is often used to diagnose or manage conditions like hyperparathyroidism (too much PTH), hypoparathyroidism (too little PTH), or kidney-related disorders that affect calcium balance. It’s also useful in evaluating symptoms like muscle weakness, fatigue, or abnormal bone density.
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
Short name
PTH (Serum)
Frequently asked questions
How often will I need this test?
What if my results are outside the normal range?
Can I eat or drink anything 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