Skip to content

Parathyroid Hormone (Active, Intact)

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

This test measures your active, intact form of parathyroid hormone (PTH), a key hormone that regulates calcium levels in your blood.

Quick summary

["Active PTH helps balance calcium and phosphorus, supporting healthy bones, nerves, and muscles."]

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

Key facts at a glance

LOINC
72203-3
Short code
PTH-Intact IO pnl SerPl
Synonyms
PTH-Intact IO pnl SerPl
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
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 order this test if you have symptoms like bone pain, frequent fractures, muscle weakness, or abnormal calcium levels. It’s also checked when evaluating conditions like hypoparathyroidism, hypercalcemia, or kidney disease.

What to Expect Before the Test

No special preparation is needed. A blood sample will be taken from a vein in your arm. You may feel slight discomfort, but it’s usually over quickly.

What the Results Mean

Results help determine if your PTH levels are too high or too low, which can affect your calcium balance and overall health. Your doctor will interpret the results in relation to your symptoms and medical history.

Common Conditions Affecting Results

Conditions like kidney disease, vitamin D deficiency, or certain cancers can influence PTH levels. Your doctor will consider these factors when reviewing your results.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: serum

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.

PTH is essential for maintaining calcium homeostasis. Low levels may indicate hypoparathyroidism, while high levels could signal hyperparathyroidism or other metabolic issues. Abnormal results prompt further evaluation to identify underlying causes.

Short name

PTH (Active)

Frequently asked questions

What causes abnormal PTH levels?
Abnormal PTH levels can result from conditions like kidney disease, thyroid disorders, vitamin D deficiency, or certain cancers. Medications, dietary factors, and genetic factors may also play a role.
How long does it take to get results?
Results are typically available within 1 to 3 business days, depending on your lab’s processing time. Your doctor will contact you once they’re ready.
Can diet affect PTH test results?
Dietary calcium and vitamin D intake can influence PTH levels, but your doctor may not require specific dietary restrictions before testing. Focus on hydration and avoiding excessive caffeine or alcohol before your blood draw.
  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