Parathyroid Hormone (Active), Intact
This test measures the active form of your parathyroid hormone (PTH), a key regulator of calcium levels in your body. It helps assess whether your thyroid glands are working properly to maintain healthy blood calcium.
["Your doctor may order this test to check for conditions affecting calcium balance, such as hypoparathyroidism or hyperparathyroidism."]
Key facts at a glance
- LOINC
- 16162-0
- Short code
- PTH-Intact 30M p chal SerPl-mCnc
- Synonyms
- PTH-Intact 30M p chal SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 80
- Ref high
- 200
- Critical range
- 20 N/A – 400 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 Matters for Your Health
PTH plays a vital role in keeping your body’s calcium and phosphate levels balanced. Low PTH can lead to symptoms like muscle cramps, numbness, or irregular heart rhythms, while high levels may cause bone pain, kidney stones, or fatigue. This test helps identify whether your body is producing enough active PTH to support these processes.
What to Expect Before the Test
No special preparation is needed for this blood test. You may have a small needle inserted into your arm or hand to draw a blood sample. If you’re on blood thinners or have a history of bleeding issues, let your doctor know beforehand.
Common Conditions This Test Helps Diagnose
This test is often used to diagnose or monitor conditions like hypoparathyroidism (low PTH), hyperparathyroidism (high PTH), vitamin D deficiency, or kidney disease. It may also be checked after thyroid surgery or in cases of unexplained calcium imbalances.
What Your Results Mean
Results are interpreted by your healthcare provider based on your overall health, symptoms, and other lab values. While reference ranges vary by lab, very low or very high levels may signal underlying issues that need further evaluation.
Reference range
Adult: 80-200 ng/dLN/A
Take your thyroid medication after the blood draw if applicable. No fasting required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Parathyroid hormone (PTH) is essential for maintaining calcium homeostasis. When levels are too low, your body may struggle to absorb calcium from food or release it from bones, potentially causing muscle weakness, bone loss, or nerve damage. Conversely, high PTH can lead to calcium deposits in tissues, kidney stones, or weakened bones over time. This test helps detect imbalances early to guide treatment, such as dietary changes, vitamin D supplements, or medical interventions.
Short name
Intact PTH
Frequently asked questions
How often should I get this test?
What are typical symptoms that might lead to 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 17, 2026. · Read our editorial policy