Parathyroid Hormone (PTH) Test

What is a Parathyroid Hormone (PTH) Test?

The Parathyroid Hormone (PTH) Test is a blood test used to measure the amount of parathyroid hormone present in the body. Parathyroid hormone is released by the parathyroid glands located near the thyroid gland in the neck. PTH helps regulate the amounts of calcium and phosphorus in the body.

Types of PTH Tests

There are two types of PTH tests: Intact PTH and N-terminal fragment PTH. Intact PTH measures the entire molecule of PTH. N-terminal fragment PTH measures a fragment of the molecule. The type of test used depends on the laboratory and the patient’s particular situation.

Why is a PTH Test Done?

A PTH test is usually done to check the levels of parathyroid hormone in the body when a person experiences symptoms such as weak and brittle bones, or to evaluate bone health in patients at risk for conditions such as osteoporosis. It may also be ordered to diagnose disorders of the parathyroid glands such as overactivity or underactivity.

When is a PTH Test Performed?

A PTH test is ordered when a patient has symptoms of problems with the parathyroid glands such as muscle weakness, bone pain, and fatigue. It is also used to evaluate bone health in patients at risk for conditions such as osteoporosis. The test may also be ordered if a patient’s calcium levels are abnormal.

How to Prepare for a PTH Test?

No special preparation is required for a PTH Test. Your doctor may ask you to stop taking any medications that may affect PTH levels, such as diuretics or calcium supplements. It is important to let your doctor know about any medications you are currently taking, as well as any other factors that may affect your test results.

What Does a Normal PTH Test Result Mean?

A normal PTH test result is usually between 10-65 pg/mL. A low result may indicate underactivity of the parathyroid glands or hypoparathyroidism. A high result may indicate hyperparathyroidism.

Risks of a PTH Test

A PTH test is generally an uncomplicated procedure with minimal risks. The most common risks are associated with the blood test itself, such as pain, bruising, and infection at the injection site. Patients should inform their doctor about any existing health conditions that may increase the risk of complications.