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Calcitonin, Serum/Plasma — Mass Concentration

Published: August 9, 2026Updated: August 16, 2026

A blood test that measures calcitonin, a hormone made by thyroid C cells. It may help evaluate thyroid nodules and other possible causes of elevated calcitonin.

Quick summary

["This test measures calcitonin in the blood to help evaluate certain thyroid conditions and possible causes of an elevated level."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
21132-6
Short code
Calcit 1M p 0.5 ug/kg Pg IV SerPl-mCnc
Synonyms
Calcit 1M p 0.5 ug/kg Pg IV SerPl-mCnc
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What is this test?

This test measures the concentration of calcitonin in serum or plasma. Calcitonin is a hormone released by C cells in the thyroid gland and is primarily used as a marker of thyroid C-cell activity.

Why might I need this test?

Calcitonin may be ordered to evaluate a thyroid nodule, investigate an abnormal thyroid finding, or assess for medullary thyroid carcinoma. It may also be used to monitor certain thyroid conditions.

How is the test performed?

A blood sample is collected by venipuncture, and the laboratory measures the amount of calcitonin in the serum or plasma using a laboratory assay.

How do I prepare for the test?

No special preparation is usually required unless your healthcare professional gives you different instructions. Tell the laboratory if you take biotin supplements, because some hormone assays can be affected by biotin.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

An elevated calcitonin level may occur with medullary thyroid carcinoma, but it can also result from other thyroid conditions, kidney impairment, medications, or laboratory assay interference. A low or undetectable level is less commonly used for diagnosis and does not by itself establish a specific illness. Results should be interpreted with your symptoms, examination, imaging, and other thyroid tests.

Short name

Calcitonin

Frequently asked questions

What does the calcitonin test measure?
It measures the concentration of calcitonin, a hormone produced by thyroid C cells, in serum or plasma.
Do I need to fast before this test?
Fasting is generally not required. Follow any preparation instructions provided by your healthcare professional or laboratory.
Does an elevated result mean I have thyroid cancer?
No. Elevated calcitonin can have several causes, including benign thyroid conditions and medication effects. Your clinician will interpret the result alongside your other findings and may recommend additional testing or follow-up.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy