Parathyroid Hormone (PTH) Test: Calcium Balance Explained
Parathyroid hormone controls the amount of calcium in your blood. When calcium is out of balance, a PTH test helps explain why. A typical reference range is about 10 to 65 pg/mL, but PTH is always interpreted together with calcium, vitamin D, and sometimes phosphate. High PTH with high calcium often points to primary hyperparathyroidism, while low calcium with high PTH suggests a secondary cause such as vitamin D deficiency. Walk-in collection makes it easy to bundle PTH with calcium and vitamin D. This guide explains the patterns and how to prepare.
Key Takeaways
- PTH is the main hormone regulating blood calcium and is interpreted with calcium, vitamin D, and phosphate.
- A typical PTH reference range is about 10 to 65 pg/mL, varying by laboratory.
- High PTH with high calcium commonly points to primary hyperparathyroidism.
- Low calcium with high PTH suggests a secondary cause such as vitamin D deficiency or kidney disease.
- PTH is usually collected alongside calcium and vitamin D for accurate interpretation.
Frequently Asked Questions
What is a normal PTH level?
A typical range is about 10 to 65 pg/mL, but the result must be read with your calcium level and your own lab's reference range.
What does high PTH with normal calcium mean?
It may suggest normocalcemic hyperparathyroidism or a secondary cause such as vitamin D deficiency, and it usually needs further evaluation.
Do I need to fast for a PTH test?
Fasting is usually not required, but follow the instructions provided with your test order.
Can I order a PTH test without a doctor?
Yes. Direct-access lab testing lets you order PTH, calcium, and vitamin D and visit a local collection site without a physician's order.
Sources
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