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Parathyroid Hormone (Active, Intact)

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

This test measures the active, intact form of parathyroid hormone (PTH), a key regulator of calcium levels in your body.

Quick summary

["Active PTH helps balance calcium, affecting bone health and nerve function."]

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

Key facts at a glance

LOINC
50528-9
Short code
PTH-Intact sp4 SerPl-mCnc
Synonyms
PTH-Intact sp4 SerPl-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
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 Is This Test Done?

Your doctor may order this test to check for conditions affecting calcium metabolism, such as hypoparathyroidism (low PTH), hyperparathyroidism (high PTH), or kidney disease. It may also be used to monitor treatment for conditions like vitamin D deficiency or bone disorders.

What Does a Low or High Level Mean?

Low levels of active PTH might suggest hypoparathyroidism, where your body doesn’t produce enough PTH, potentially leading to low calcium and muscle spasms. High levels could indicate overactive parathyroid glands or kidney problems that interfere with calcium regulation.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is sent to a lab where the active, intact PTH is measured using a specialized immunoassay method.

What Should You Do Before the Test?

No special preparation is needed, but inform your doctor about any medications, supplements, or recent calcium intake that might affect 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.

◆Associated findings1

Short name

PTH (Active)

Frequently asked questions

What causes abnormal PTH levels?
Abnormal PTH levels can result from conditions like hypoparathyroidism (low PTH), hyperparathyroidism (high PTH), kidney disease, vitamin D deficiency, or certain medications. Chronic kidney disease often requires monitoring PTH levels to manage bone and mineral disorders.
How often should I get this test?
Frequency depends on your health condition. Your doctor will determine how often you need retesting based on your symptoms, medical history, and treatment plan.
Can diet affect PTH test results?
Dietary calcium intake can influence calcium levels, which may indirectly affect PTH. However, avoid extreme calcium supplements or foods just before testing unless advised by your doctor.
  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