Calcitonin Blood Test: What You Need to Know

A Calcitonin Blood Test is a blood test that measures the level of calcitonin in your blood. This test is often used to help diagnose and monitor certain types of thyroid cancer. In this article, we will discuss the preparations, procedures, and result interpretations of a calcitonin test.

Overview about Calcitonin Blood Test

Blood Calcitonin is a hormone produced by the C cells of the thyroid gland, which helps to lower the levels of blood calcium. In contrast, calcium is a mineral that is essential for many bodily functions, including muscle and nerve function, blood clotting, and bone health.

When the calcium level in the blood is too high, the C cells of the thyroid gland release calcitonin, which helps to lower the calcium level by inhibiting the release of calcium from the bones and increasing the excretion of calcium through the kidneys. In this way, calcitonin helps to maintain the balance of calcium in the blood.

However, the calcitonin blood test is not directly used to measure calcium levels in the blood. Instead, it measures the level of calcitonin, which can be useful in diagnosing and monitoring medullary thyroid cancer (MTC).

Medullary thyroid cancer is a rare type of thyroid cancer that accounts for about 5-10% of all cases of thyroid cancer. It arises from the C cells of the thyroid gland and can produce abnormally high levels of calcitonin. Serum calcitonin test is a sensitive and specific test for the diagnosis of medullary thyroid cancer.

The calcitonin test is also used to monitor the treatment of medullary thyroid cancer. After surgery to remove the thyroid gland (thyroidectomy), the level of calcitonin in the blood should decrease to very low levels. If the level of calcitonin remains high, it may indicate that some of the cancerous tissue was not removed during surgery, or that the cancer has spread to other parts of the body.

In addition to its use in the diagnosis and treatment of medullary thyroid cancer, the calcitonin test may also be used to diagnose and monitor other conditions that affect the thyroid gland, such as autoimmune thyroiditis and thyroid nodules.

• A thyroid nodule that feels hard or irregular.
• Swelling or enlargement of the thyroid gland.
• Hoarseness or other changes in voice.
• Difficulty swallowing.
• Persistent cough, especially if accompanied by bloody sputum.
• Enlargement of lymph nodes in the neck.
• Pain in the neck, throat, or ears.
• Unexplained weight loss or loss of appetite.

It is important to note that these symptoms can be caused by other conditions as well, and having any of these symptoms does not necessarily mean that a person has MTC. However, if a healthcare provider suspects MTC, they may order a calcitonin test in addition to other diagnostic tests, such as imaging studies or a biopsy, to help confirm the diagnosis.

Preparations for a Calcitonin Test

Before undergoing a Calcitonin Blood Test, there are a few preparations that need to be made. Your doctor will give you specific instructions, but in general, you may need to:

1. Fasting for 12 hours before the test: You will need to avoid eating or drinking anything, except water, for 12 hours before the test.
2. Avoid certain medications: Certain medications, such as proton pump inhibitors, can affect the results of a calcitonin test. Your doctor will tell you which medications to avoid before the test.
3. Inform your doctor of any recent procedures: Some procedures, such as a biopsy, can also affect the results of a calcitonin test. Inform your doctor of any recent procedures you have undergone.

Procedures for a Calcitonin Blood Test

The calcitonin test is a simple blood test that is performed at a laboratory. The procedure usually involves the following steps:

1. A healthcare professional will clean the area around your arm with an antiseptic and insert a needle into a vein in your arm.
2. A small sample or, amount of blood will be drawn and collected in a tube.
3. The needle will be removed, and a bandage will be placed over the site to stop any bleeding.

The entire procedure usually takes only a few minutes, and you can resume your normal activities immediately afterward.

“Related: Renin Blood Test, Everything You Need to Know this test“

Result Interpretations

The normal range for calcitonin in the blood is less than 10 picograms per milliliter (pg/mL). However, the normal range may vary slightly depending on the laboratory that performs the test.

If the results of the Calcitonin Blood Test are higher than normal, your doctor may recommend additional tests to determine the cause of the high levels. Depending on the underlying condition, treatment options may include surgery, radiation therapy, chemotherapy, or medication.
Interpretation of the calcitonin test results will depend on the context of the patient’s clinical presentation, including the presence or absence of a thyroid nodule or thyroid cancer, family history, and other factors. In general, the following results may be interpreted as:

• Normal: Normal levels of calcitonin in the blood typically range from 0 to 10 pg/mL. This result may indicate that there is no evidence of MTC or other thyroid diseases.
• Elevated: Elevated levels of calcitonin may indicate the presence of MTC (a rare type of thyroid cancer), or other thyroid diseases. However, other factors, such as recent thyroid surgery, inflammation, or certain medications, may also cause elevated calcitonin levels.
• Moderately elevated: Calcitonin levels between 10 and 100 pg/mL are considered moderately elevated. This result may indicate a higher risk of MTC or other thyroid diseases, and further testing, such as imaging studies or a biopsy, may be recommended.
• Significantly elevated: Calcitonin levels above 100 pg/mL are considered significantly elevated and strongly suggest the presence of MTC. Additional diagnostic testing and evaluation may be necessary to confirm the diagnosis, determine the extent of the disease, and plan treatment.

It is important to note that the calcitonin test is not a definitive diagnostic tool for MTC, and other tests, such as imaging studies and biopsies, may be necessary to confirm the diagnosis. Additionally, some individuals with MTC may have normal or only slightly elevated calcitonin levels, and other tests, such as genetic testing, may be necessary for diagnosis.

Related tests

• TSH
• Thyroglobulin
• Thyroid ultrasound.
• Fine-needle aspiration biopsy.
• Thyroid scan.
• Genetic testing.
• CT scan or MR.

In conclusion, a Calcitonin Blood Test measures the level of hormone calcitonin in the blood. This test is often used to help diagnose and monitor certain types of thyroid cancer. Before undergoing a calcitonin test, it is important to follow your doctor’s instructions and inform them of any recent procedures or medications. If the results of the test are higher than normal, additional tests may be necessary to determine the underlying cause.