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Parathyroid Hormone (Intact)

Published: August 9, 2026Updated: August 16, 2026

This test measures the total amount of active parathyroid hormone (PTH) in your blood, which helps regulate calcium levels in your body.

Quick summary

["PTH helps control calcium and bone health; abnormal levels may signal conditions like hypoparathyroidism or hyperparathyroidism."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
22421-2
Short code
M avium paraTB Ab Ser Ql
Synonyms
M avium paraTB Ab Ser Ql
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 Matters

PTH plays a critical role in maintaining healthy calcium and phosphorus levels in your blood. Low PTH can lead to muscle cramps, numbness, or seizures, while high PTH may cause bone pain, kidney stones, or weak bones.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the draw if your doctor recommends it. Bring your lab results and current medications to your appointment.

How the Test Works

A blood sample is taken from a vein in your arm. The lab then uses an immunoassay method to detect and measure intact PTH levels in your serum or plasma.

Possible Results & Next Steps

Results are compared to a reference range specific to your age and health. If your levels are outside the normal range, your doctor may recommend further testing or adjustments to your treatment plan.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: PTH Levels and Health

Short name

Intact PTH

Frequently asked questions

What does a high PTH level mean?
High PTH may indicate hyperparathyroidism, where your parathyroid glands produce too much hormone. This can lead to calcium buildup in your kidneys, bones, or blood vessels. It may also cause fatigue, kidney stones, or weak bones.
What does a low PTH level mean?
Low PTH can signal hypoparathyroidism, where your body doesn’t produce enough hormone. This may cause muscle spasms, numbness, or irregular heartbeat. It can also lead to low calcium levels, which may require calcium supplements or vitamin D.
How often should I get this test?
Your doctor will determine how often you need this test based on your medical history, symptoms, and other test results. Regular monitoring may be needed if you have conditions like kidney disease, osteoporosis, or thyroid disorders.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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