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. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.
Why the Test is Performed
Calcitonin is a hormone produced in C cells of the thyroid gland. The thyroid gland is located inside the front of your lower neck. Calcitonin helps control the breakdown and rebuilding of bone.
Your health care provider may order a calcitonin test when you have symptoms of medullary cancer of the thyroid or multiple endocrine neoplasia (MEN) syndrome, or a family history of these conditions. Calcitonin may also be higher in other tumors, such as:
- Insulinoma (tumor in the pancreas that produces too much insulin)
- Lung cancer
- VIPoma (cancer that usually grows from islet cells in the pancreas)
A normal value is less than 10 pg/mL.
Women and men can have different normal values, with men having higher values.
Sometimes, calcitonin in the blood is checked several times after you are given a shot (injection) of a special medicine that stimulates calcitonin production.
You will need this extra test if your baseline calcitonin is normal, but your doctor suspects you have medullary cancer of the thyroid.
Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or may test different specimens. Talk to your doctor about the meaning of your specific test results.
What Abnormal Results Mean
A higher-than-normal level may indicate:
- Lung cancer
- Medullary cancer of thyroid (most common)
Higher-than-normal levels can also occur in people with kidney disease, smokers, higher body weight, and when taking certain medicines to stop stomach acid production.
Veins and arteries vary in size from one person 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:
- Excessive bleeding
- Fainting or feeling lightheaded
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)
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. 13th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 28.
Chernecky CC, Berger BJ. Calcitonin (thyrocalcitonin) - serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:276-277.