Parathyroid hormone (PTH) blood test

A blood sample is needed.

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.

PTH is released by the parathyroid glands. The 4 small parathyroid glands are located in the neck, near or attached to the back side of the thyroid gland. The thyroid gland is located in the neck, just above where your collarbones meet in the middle. PTH controls calcium, phosphorus, and vitamin D levels in the blood.…

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 provider about the meaning of your specific test results. Try to go back to the same lab each time you need to…

A higher-than-normal level may occur with: Disorders that increase phosphate or phosphorous levels in the blood, such as long-term (chronic) kidney disease Failure of the body to respond to PTH (pseudohypoparathyroidism) Lack of calcium, which may be due to not eating enough calcium, not absorbing calcium in the gut,…

There is little risk involved with having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others. Other risks associated with having blood drawn are slight, but may include: Excessive…

Bringhurst FR, Demay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Melmed S, Auchus RJ, Goldfine AB, Koenig RJ, Rosen CJ, eds. Williams Textbook of Endocrinology . 14th ed. Philadelphia, PA: Elsevier; 2020:chap 29. Klemm KM, Klein MJ, Zhang Y. Biochemical markers of bone metabolism. In:…