Blood Calcium & PTH Relationship

Parathyroid hormone (PTH) helps the body maintain stable levels of calcium in the blood. When patients show an abnormal value of blood calcium, PTH is usually tested to determine the cause.  Testing both calcium and PTH helps to reveal how well your parathyroid glands are functioning.

Normal Range

Normal blood calcium ranges from 8.5 – 10.2 mg/dl.

Normal PTH ranges from 10 – 65 pg/ml.

Calcium PTH Interpretation
Normal Normal Calcium regulation system functioning OK
Low High PTH is responding correctly; may run other tests to check for other causes of hypocalcemia
Low Normal or Low PTH not responding correctly; probably have hypoparathyroidism
High High Parathyroid gland producing too much PTH; may do imaging studies to check for hyperparathyroidism
High Low PTH is responding correctly; may run other tests to check for non-parathyroid-related causes of elevated calcium
Normal High Mild hyperparathyroidism
* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.