Can this result diagnose a condition on its own?

No. Laboratory results are interpreted with symptoms, medical history, specimen conditions and related tests.

Which reference range should I use?

Start with the performing laboratory's own reference interval; clinical cutoffs, when relevant, are separate sourced thresholds used for a specific purpose.

When should I discuss the result with a healthcare professional?

Results that are clearly outside range, persistent, symptomatic or unexpected should be reviewed by a healthcare professional.

Information about a laboratory test

PTH: What Does This Test Measure?

The PTH test measures parathyroid hormone concentration and regulation of calcium-phosphate balance.

Test summary

Test name: PTH
Abbreviations: PTH, iPTH
Category: Hormones / Parathyroid
Panel: Bone & Mineral Metabolism
Specimen: Serum / plasma
Common units: pg/mL, pmol/L

What does the test measure?

The PTH test measures parathyroid hormone concentration and regulation of calcium-phosphate balance.

Why is the test ordered?

Ordered with related tests to assess mineral balance, kidney/endocrine regulation or bone metabolism.

Information about a low result

Low PTH should be interpreted with serum calcium; it can occur in different contexts including low magnesium or impaired parathyroid function.

Information about a high result

High PTH has different implications depending on whether calcium is low, normal or high; vitamin D, phosphate and kidney function provide context.

Reference and clinical context

Start with the performing laboratory's reference interval, unit, specimen type and method. Numeric information on this page is stored as sourced example intervals or clinical thresholds.

Reference range 1

>= 10 – <= 65 pg/mL

Population: Adults / general example
Age range: 18
Specimen: Serum / plasma

Sourced example reference interval for PTH

This is a sourced example reference interval; laboratory, method, age and clinical context can change the range. The user's own report takes priority.

Reference ranges may vary by laboratory, method used, age, sex, pregnancy status, and clinical context. The reference range on your own laboratory report takes precedence.

Interpretation notes

PTH should not be interpreted independently of calcium. A PTH value within the reference interval may still be physiologically inappropriate when calcium is high.

Related specialties

Endocrinology
Internal Medicine
Nephrology
Family Medicine

Frequently asked questions

More information about this test

Sources

Vitamin D – Health Professional Fact Sheet — NIH Office of Dietary Supplements
U.S. government nutrition reference · 2025 · 25(OH)D as vitamin D status marker and FNB concentration categories · Verified: Aug 12, 2026
Calcium Blood Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2025 · Total calcium purpose, albumin context and example adult reference interval · Verified: Aug 12, 2026
Magnesium Blood Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2023 · Magnesium testing, kidney/intestinal regulation and related minerals · Verified: Aug 12, 2026
Phosphate in Blood — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2023 · Phosphate interpretation with calcium, PTH, vitamin D and kidney function · Verified: Aug 12, 2026
Parathyroid Hormone (PTH) Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2023 · PTH interpretation with calcium · Verified: Aug 12, 2026
Parathyroid Hormone (PTH) Blood Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2025 · Example PTH interval and calcium-dependent interpretation · Verified: Aug 12, 2026