|Back to Main Print This Page Email to a Friend|
The PTH test measures the level of parathyroid hormone in the blood.
PTH stands for parathyroid hormone. It is a protein hormone released by the parathyroid gland.
A laboratory test can be done to measure the amount of PTH in your blood.
Parathormone; Parathormone (PTH) intact molecule
A blood sample is needed. For information on how this is done, see: Venipuncture
Ask your health care provider if you should stop eating or drinking for some period of time before the test. Most often, you will not need to fast or stop drinking.
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.
Parathyroid hormone (PTH) is released by the parathyroid glands. The four tiny parathyroid glands are located in the neck, near or attached to the back side of the thyroid gland. PTH controls calcium, phosphorus, and vitamin D levels in the blood. It is important for regulating bone growth. Your health care provider may order this test if:
To help understand whether your parathyroid hormone level is normal, your doctor will measure your blood calcium at the same time.
Normal values are 10 to 55 picograms per milliliter (pg/mL).
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different specimens. Talk to your doctor about the meaning of your specific test results.
A higher-than-normal level may occur with:
A lower-than-normal level may occur with:
Other conditions for which the test may be ordered include:
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
Bringhurst FR, Demay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology. 12th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 28.
Wysolmerski JJ, Insogna KL. The parathyroid glands, hypercalcemia, and hypocalcemia. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, Pa: Elsevier Saunders; 2011:chap 253.