Definition
Calcitonin is a test that measures the amount of the hormone calcitonin in the blood.
How the test is performed
Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
How to prepare for the test
There is usually no special preparation needed.
How the test will feel
When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Why the test is performed
The health care provider may suggest a calcitonin test when symptoms indicate medullary thyroid cancer or MEN syndrome, or the patient has a family history of these conditions. Calcitonin may also be higher in other tumors, such as:
- Insulinomas
- Lung cancer
- VIPomas
Calcitonin is a hormone produced in the C cells of the thyroid gland. Its role in humans is unclear. In animals, calcitonin helps to regulate blood calcium by slowing down the amount of calcium released from the bones. Calcitonin works in the opposite way as parathyroid hormone (PTH) and 1,25-dihydroxy vitamin D.
