Serum or plasma concentration of **parathyroid hormone (PTH)**
This test measures the amount of parathyroid hormone in your blood, which helps regulate calcium levels in your body.
["PTH helps balance calcium and phosphorus, affecting bone health and nerve function."]
Key facts at a glance
- LOINC
- 47772-9
- Short code
- GH 45M p Arg SerPl-aCnc
- Synonyms
- GH 45M p Arg SerPl-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- 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 order this test to check for conditions affecting calcium metabolism, such as hypoparathyroidism (low PTH), hyperparathyroidism (high PTH), or kidney disease. It can also help diagnose or monitor conditions like osteoporosis, vitamin D deficiency, or certain cancers.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the draw if your lab uses a specific method. Wear a loose shirt for easy access to your arm.
During the Test
A healthcare provider will insert a small needle into a vein in your arm to collect blood. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to the lab for testing.
After the Test
You can resume normal activities immediately. Apply gentle pressure to the site to stop bleeding, and check for any redness or swelling. Report any unusual symptoms like dizziness or fainting to your doctor.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
High PTH levels may indicate overactive parathyroid glands, leading to conditions like osteoporosis, kidney stones, or bone pain. Low PTH can cause muscle cramps, numbness, or seizures due to dangerously low calcium. Monitoring PTH helps guide treatment for these conditions.
Short name
PTH Level
Frequently asked questions
How long does it take to get my results?
Can diet affect PTH test results?
Is there anything I should avoid 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