What Is Parathyroid Hormone?
PTH is produced by four small parathyroid glands in your neck. It regulates calcium, phosphorus and vitamin D levels in your blood and bones.
Normal PTH Range
| Test | Normal Range |
|---|---|
| Intact PTH | 10–65 pg/mL |
| Calcium (paired test) | 8.5–10.5 mg/dL |
What High PTH Means
Primary Hyperparathyroidism
One or more parathyroid glands overproduce PTH, usually from a benign tumour, raising blood calcium and weakening bones.
Secondary Hyperparathyroidism
Glands overproduce PTH in response to low calcium, often from kidney disease or vitamin D deficiency.
What Low PTH Means
Hypoparathyroidism can result from gland damage during neck surgery, autoimmune disease or genetic conditions, leading to low calcium and symptoms like muscle cramps and tingling.
Symptoms of Abnormal PTH
- Bone pain or fractures
- Kidney stones
- Fatigue and weakness
- Muscle cramps or tingling (low calcium)
- Excessive thirst and urination (high calcium)
Important: PTH is usually interpreted together with calcium, phosphorus and vitamin D levels. Discuss abnormal results with your doctor or an endocrinologist.