Hormones
PTH
LOINC 2731-8 · pg/mL
Ranges
Reference range: 15–65 pg/mL
What it is
Parathyroid hormone (PTH) is made by four small glands in the neck and is the main regulator of calcium in your blood.
Why it matters
It is essential for interpreting calcium problems and assessing bone and parathyroid health.
What high values can mean
A higher value can reflect overactive parathyroid glands or the body responding to low calcium or low vitamin D.
What low values can mean
A lower value can relate to underactive parathyroid glands or high calcium from another cause.
How to improve it
PTH is interpreted with calcium and vitamin D; correcting a vitamin-D deficiency can normalise a reactive rise.
Food & lifestyle
Adequate vitamin D and calcium support normal PTH; the underlying cause guides care.
Preparing for the test
A blood test, often drawn with calcium; fasting is not specifically required — follow your lab.
When to talk to a doctor
Discuss an abnormal PTH with a doctor, always interpreted together with your calcium level.
Related markers
Sources
- MedlinePlus (NIH)
- Testing.com (AACC)
Content reviewed on June 26, 2026
Medical disclaimer
This content is for educational purposes only. It is not medical advice and does not diagnose, treat, or prevent any condition. Reference ranges vary between laboratories — always use the range printed on your report and discuss your results with a healthcare professional.
See your own values in context
Bllod turns your lab report PDFs into clear, tracked results — every marker organized, explained, and charted over time.