Parathyroid Hormone (Active), Serum/Plasma Mass Concentration
This test measures the active form of parathyroid hormone (PTH), a key regulator of calcium levels in your blood. It helps assess whether your thyroid glands are functioning properly and if your body is maintaining healthy calcium balance.
["Active PTH helps diagnose conditions affecting calcium metabolism and thyroid health."]
Key facts at a glance
- LOINC
- 90741-0
- Short code
- PTH-Intact SerPl IA-mCnc
- Synonyms
- PTH-Intact SerPl IA-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
- Method
- ia
- 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 unexplained fatigue, or if they suspect conditions such as hyperparathyroidism (too much PTH) or hypoparathyroidism (too little PTH). It may also be used to monitor treatment for thyroid disorders or kidney disease.
How the Test Works
Blood is drawn from a vein in your arm. The sample is sent to a lab where it is analyzed using a sensitive immunoassay method to detect and measure the active PTH levels in your serum or plasma.
What to Expect Before the Test
No special preparation is needed for this test. You can eat and drink normally on the day of the test. If you are on medications that affect calcium or PTH levels, let your healthcare provider know.
What to Expect After the Test
After the blood is drawn, you may feel a slight pinch or bruising at the site. Most people recover quickly. Apply gentle pressure to the area to help stop any bleeding. Avoid vigorous activity for a short time.
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.
High levels of active PTH can indicate hyperparathyroidism, which may lead to conditions like osteoporosis, kidney stones, or high blood calcium. Low levels may suggest hypoparathyroidism, causing symptoms such as muscle spasms, numbness, or irregular heart rhythms. Monitoring active PTH is crucial for diagnosing and managing these conditions effectively.
Short name
Active PTH
Frequently asked questions
What does an abnormal result mean?
How often should I get this test?
Can diet or supplements affect 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