Parathyroid Hormone Intact (PTHi) - Serum
Description
This test measures the level of parathyroid hormone (PTH) in your blood. PTH, is made by your parathyroid glands. They are four pea-sized glands in your neck.
Hormones are chemical messengers in your bloodstream. They control the actions of certain cells or organs. PTH controls the level of calcium in your blood. Calcium is one of the most important minerals in your body. Most of it is stored in your bones and teeth. Having the right amount of calcium in your blood is important for your nerves, muscles, and heart to work properly.
If your calcium blood levels are too low, your parathyroid glands will release just enough PTH into your blood to return your calcium levels to normal. PTH raises your blood calcium by:
- Telling your bones to release calcium into your blood
- Helping your intestines to absorb calcium from the food you eat
- Helping your kidneys to keep calcium in your blood instead of getting rid of it through your urine (pee)
When your calcium blood levels return to normal, your parathyroid glands stop making PTH and your blood PTH levels decrease.
Because the amount of PTH in your blood changes with the amount of calcium in your blood, your health care provider will usually order a calcium blood test along with a PTH test. Comparing the results of both tests helps your provider understand if your parathyroid glands are working properly to control your calcium levels.
Other names: parathormone, intact PTH.
Source: National Institutes of Health (NIH) U.S. Department of Health and Human Services.