Skip to content

Serum Parathyroid Hormone (Active, Intact)

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

This test measures the active, intact form of parathyroid hormone (PTH) in your blood. PTH is a hormone produced by your parathyroid glands that helps regulate calcium levels in your body.

Quick summary

["Helps diagnose and monitor conditions affecting calcium balance and bone health."]

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

Key facts at a glance

LOINC
47885-9
Short code
GH 1.5h p Arg+Ins SerPl-aCnc
Synonyms
GH 1.5h p Arg+Ins SerPl-aCnc
Category
hormone
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 for Your Health

Your body relies on PTH to maintain healthy calcium and phosphorus levels, which are essential for strong bones, muscle function, and nerve signaling. Abnormal PTH levels can signal conditions like hypoparathyroidism, hyperparathyroidism, or kidney disease.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or hand to draw blood. If you’re on blood thinners, let your provider know before the test.

Common Conditions This Test Helps Identify

This test is often used to check for disorders like low or high calcium levels, bone diseases (e.g., osteoporosis), kidney problems, or vitamin D deficiencies. It may also be ordered if you have symptoms like muscle weakness, bone pain, or frequent fractures.

What the Results Might Mean

Results are interpreted by your healthcare provider based on your overall health and symptoms. Very high or very low levels may indicate underlying medical issues that need further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: PTH’s Role in Health

Short name

Active PTH (Serum)

Frequently asked questions

What causes false high or low PTH results?
False results can occur if you’re dehydrated, have recent blood loss, or are taking certain medications (e.g., calcium supplements, steroids). Your provider may repeat the test or order additional tests to confirm results.
How often should I get this test?
Your provider will determine how often you need this test based on your health history, symptoms, and treatment plan. Regular monitoring may be needed if you have chronic conditions like kidney disease or osteoporosis.
Can I eat or drink before this test?
You can eat and drink normally before the test unless instructed otherwise. Avoiding alcohol or caffeine in the 24 hours before may help ensure accurate results, but always follow your provider’s specific instructions.
  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