Parathyroid Hormone (PTH) Test
A blood test that measures parathyroid hormone, which controls calcium levels.
Quick Summary
To find the cause of high or low calcium and to check bone health in kidney disease.
Parathyroid hormone level.
No special preparation, unless your lab advises.
Overview
PTH is usually tested together with calcium and vitamin D.
High PTH with high calcium suggests an overactive parathyroid gland.
What It Measures
PTH
Blood level.
How It's Performed
- 01
Preparation
Usually no special preparation. Tell the staff about medicines you take.
- 02
Blood sample
A small amount of blood is taken from a vein in your arm with a thin needle.
- 03
Afterwards
Press on the spot for a minute. A small bruise is common; you can go back to normal activities.
Reference Ranges
Note: Normal ranges vary by laboratory. Consult your report for the specific reference used.
| Parameter | Typical Range (Adult) | Units |
|---|---|---|
| PTH | 15–65 | pg/mL |
Interpreting Results & Next Steps
Discuss with Doctor
Normal ranges differ between laboratories, ages and sexes; always use the range printed on your report and ask your doctor what your results mean.
If values are Low:
Low PTH with high calcium suggests another cause of high calcium.
If values are High:
High PTH may come from parathyroid disease, vitamin D deficiency or kidney disease.
Sources and further reading
Last updated 21 October 2026. For more detail, see these trusted health organisations.
- Parathyroid Hormone (PTH) Test(opens in a new tab) · MedlinePlus, US National Library of Medicine