A thyroid antibody blood work measures the amount of thyroid antibodies in your blood sample. The thyroid gland is a small butterfly-shaped organ situated in the neck. It produces hormones that regulate several important bodily functions in the system including metabolism, heart health and controlling the heart, nerve, and muscle function. Antibodies are proteins that the immune system makes to combat foreign elements like viruses and bacteria. However, at times antibodies mistakenly attack the healthy cells of tissues and organs, and the condition is termed autoimmune disease.

If antibodies attack your thyroid gland, they can result in severe thyroid autoimmune disease:

Hashimoto's disease, also called Hashimoto's thyroiditis, is the most common cause of hypothyroidism. When the thyroid gland doesn't make adequate thyroid hormones to meet the body's needs it results in hypothyroidism.
thyroid antibody test

Graves' disease is the cause of hyperthyroidism, where the thyroid gland makes excess thyroid hormones that the body needs.

If your doctor has diagnosed you with hypothyroidism or hyperthyroidism, a thyroid antibody test might help rule out if a thyroid autoimmune condition is causing the problem.

Also Read: Thyroid Stimulating Hormone (TSH): Structure, Crucial Functions And Adverse Effects

There are a range of tests that assess for different types of thyroid antibodies. Your doctor will recommend tests based on your symptoms, the results of other tests, and knowing about your detailed medical and family health history.

Thyroid antibody tests are also known by other names such as thyroid autoantibodies, thyroid peroxidase antibody, TPO, anti-TPO, antithyroid microsomal antibody, thyroid-stimulating immunoglobulin, TSI, and TSH receptor antibody to mention a few.

Purpose Of Thyroid Antibody Test?

If thyroid hormone levels reveal that the thyroid gland is not working properly, your doctor may recommend thyroid antibody tests to check if an autoimmune disorder is causing the issue.

Thyroid antibody tests are used to evaluate for different thyroid antibodies that affect your thyroid gland function in various ways. These antibodies include:

Thyroid peroxidase antibodies (TPOAb): High levels of these antibodies mean Hashimoto's disease is causing hypothyroidism.

Thyroglobulin antibodies (TgAb): High levels of these antibodies are an indication of Hashimoto's disease.

Thyrotropin receptor antibodies (TRAb): These antibodies can be an indication of Graves' disease.

Why Do I Need A Thyroid Antibody Test?

You may need this test if you have any symptoms of Hashimoto’s disease or Graves’ disease. However, the doctor will generally order blood works to find out if thyroid hormone levels are normal including T3, T4, and TSH to determine if you have hyperthyroidism or hypothyroidism.

Symptoms Of Hashimoto's Disease

Symptoms Of Graves' Disease :

  • Weight loss
  • Bulging of the eyes
  • Tremors in the hand
  • Low tolerance for heat
  • Trouble sleeping
  • Anxiety
  • Increased heart rate
  • Swollen thyroid, known as goitre

What Happens During A Test?

A lab technician or phlebotomist will take a blood sample from a vein in the arm with a small needle into a test tube. You may feel a mild prick when the needle goes in or out.

Also Read: Thyroid Disorders In Pregnancy: Causes, Symptoms And Treatment

Preparation

There are no specific preparations required for a thyroid antibodies blood test.

Risks

There is very little risk of having a blood test. You may feel mild pain or bruising at the spot where the needle was inserted, and most symptoms settle away quickly.

What Does The Results Mean?

Negative: No thyroid antibodies were seen. This means your symptoms are not caused by an autoimmune disease.

Positive: Thyroid antibodies, TPOAb and/or TgAb, were found. This indicates you have Hashimoto's disease. Usually, people with Hashimoto's disease have high levels of one or both of these types of antibodies.

Thyroid antibodies, TPOAb and/or TRAb, were found. This indicates you have Graves' disease.

The presence of thyroid antibodies in excess amounts indicates you are more prone to have an autoimmune disorder of the thyroid gland.

Thyroid disease can worsen during pregnancy, which can harm both the mother and her foetus. Pregnant women with thyroid disease should be tested for thyroid antibodies along with other tests that determine thyroid hormone levels. Medications are prescribed to treat thyroid disease and are safe to be taken during pregnancy.