Calcitonin Test
The calcitonin test is a medical laboratory test used to measure the level of calcitonin in the blood. Calcitonin is a hormone produced by the thyroid gland, specifically by the parafollicular cells (also known as C-cells), which are located in the thyroid gland.
Purpose of the Test
The primary purpose of the calcitonin test is to diagnose and monitor medullary thyroid cancer (MTC), a rare type of thyroid cancer that originates from the parafollicular cells. Elevated levels of calcitonin in the blood can indicate the presence of MTC.
How the Test is Performed
The calcitonin test involves taking a blood sample from a vein, usually in the arm. The blood sample is then sent to a laboratory for analysis, where the level of calcitonin is measured using a radioimmunoassay or enzyme-linked immunosorbent assay (ELISA) technique.
Interpretation of Results
The normal range for calcitonin levels in the blood varies depending on the laboratory and the specific test used. Generally, a normal calcitonin level is considered to be less than 10 pg/mL. Elevated levels of calcitonin can indicate MTC or other conditions such as:
- Thyroiditis (inflammation of the thyroid gland)
- Pulmonary neuroendocrine tumors
- Familial medullary thyroid carcinoma
- Multiple endocrine neoplasia type 2 (MEN2)
Precautions and Limitations
The calcitonin test is not foolproof, and false-positive or false-negative results can occur. Certain medications, such as calcium and vitamin D supplements, can affect calcitonin levels. Additionally, the test may not be able to detect early stages of MTC.
Uses in Clinical Practice
The calcitonin test is used in clinical practice for:
- Diagnosing and monitoring medullary thyroid cancer (MTC)
- Screening family members of patients with MTC or MEN2 for genetic mutations
- Monitoring patients with a history of MTC or other conditions that affect calcitonin levels
Additional Information
The calcitonin test is often used in conjunction with other diagnostic tests, such as ultrasound, computed tomography (CT) scans, and fine-needle aspiration biopsy, to confirm a diagnosis of MTC or other conditions. The test may also be used to monitor the effectiveness of treatment for these conditions.
Article last updated on: 15th June 2025.
If you have any feedback, please get in touch.
Diagnosis Pad
Medical AI Assistant with Differentials, Guidance, Transcriptions, Notes, Medical Encyclopedia and Explainable AI.
Medical AI Assistant with Differentials, Guidance, Transcriptions, Notes, Medical Encyclopedia and Explainable AI.
Available for iOS, macOS and Android.
Medical Disclaimer
The information provided is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay seeking it because of something you have read on this site. We we do not guarantee, and assume no legal liability or responsibility for the accuracy, currency, or completeness of the information provided.