hand holding a vial in a lab

Thyroid Antibody Test: What Is It and When Do You Need One?

hand holding a vial in a lab

The thyroid gland is a butterfly-shaped gland located at the front of the neck. This gland produces hormones that help to regulate the body’s metabolism. The immune system produces chemicals called antibodies, which are supposed to attack foreign substances (such as bacteria or viruses) to protect the body.

Sometimes, the immune system mistakenly attacks itself, an autoimmune response. If the body’s immune system mistakenly attacks the thyroid cells, then your body will have something called “thyroid antibodies.” This is what a thyroid antibody test looks for.

What is a thyroid antibody test, and what is it used for?

The thyroid antibody test looks for thyroid antibodies in the blood to help diagnose certain diseases. A couple of different types of thyroid antibodies are associated with different types of autoimmune diseases. When antibodies attack the thyroid gland, it can lead to a variety of different health issues.

scientist looking through microscope

Types of thyroid antibody tests

Thyroid antibodies are not all the same. There are different types of thyroid antibodies that all affect thyroid tissues differently. One type of thyroid antibody may destroy thyroid tissue, while another could cause the thyroid to make too much of a certain hormone. Some common types of thyroid antibodies include:

  • Thyroid peroxidase antibody (TPOAb). This type of thyroid antibody may indicate that an individual has Hashimoto’s or Graves’ disease.
    • Hashimoto’s disease is sometimes also referred to as Hashimoto thyroiditis. This autoimmune disease commonly causes hypothyroidism, an underactive thyroid.
    • Graves’ disease is another type of autoimmune disease that commonly causes hyperthyroidism which is the opposite of hypothyroidism or an overactive thyroid.
  • Thyroglobulin antibody (Tg Ab). This type of thyroid antibody may also be seen in Hashimoto’s disease. Many people who have Hashimoto’s disease have high levels of both Tg and TPO antibodies.
  • Thyroid-stimulating hormone receptor antibody (TSHR Ab/TRAb). TSHR antibody is commonly raised in Graves’ disease. This stimulatory antibody can increase thyroid activity.
  • Thyroid-stimulating immunoglobulin (TSI Ab). This thyroid antibody is unique to Graves’ disease and causes an overactive thyroid. TSI antibody is not routinely tested for and is usually used for research purposes.
scientist writing down something in a notebook

What are the benefits of getting tested?

The main benefit of getting a thyroid antibody test is that it can offer a definitive diagnosis if you think you may be suffering from a thyroid condition. Results from this type of test can help you figure out if you have an autoimmune disease or not. Having a clear understanding of what’s going on in your body can help your doctor guide treatment.

How do you know when you need a thyroid antibody test?

Most people get a thyroid antibody test because they’ve been experiencing thyroid disorder symptoms . If you’ve had other types of thyroid tests done that came back abnormal – such as those that look at thyroid hormones or thyroid stimulating hormone – your doctor may order a thyroid antibody test to get a clearer picture of what’s happening.

Common symptoms of Hashimoto’s disease include:

  • Unexplained weight gain
  • Fatigue
  • Hair loss
  • Feeling unusually cold
  • Irregular periods in women
  • Constipation
  • Depression
  • Joint pain

Common symptoms of Graves’ disease include:

  • Unexplained weight loss
  • Eyes that bulge out
  • Hand tremors
  • Hot flashes
  • Insomnia
  • Anxiety
  • Increased heart rate
  • Goiter or swelling of the thyroid

Thyroid antibodies may be tested in someone who has been found to have high or low levels of other types of thyroid hormones, such as T3, T4, and TSH. T3 and T4 are hormones released by the thyroid. For this reason, high T3 or T4 usually indicate hyperthyroidism, while low levels of T3 or T4 usually indicate hypothyroidism.

TSH, or thyroid stimulating hormone, is not released by the thyroid but by the pituitary gland. TSH helps to stimulate the thyroid to release hormones. So, high levels of TSH may indicate that the thyroid itself is underactive because the pituitary is releasing many hormones to get the thyroid to work normally.

What do the results mean?

If your test returns positive for thyroid antibodies that point to Hashimoto’s disease, you may need to take synthetic thyroid hormones to compensate for those lacking. If your test returns positive for thyroid antibodies that indicate Graves disease, you’ll likely be prescribed an antithyroid agent to help with the excess in thyroid hormones. In some cases, Graves’ disease may need to be treated with radiation therapy or surgery if the medication does not work.

graphs and lines as test results

If your thyroid antibody test returns negative for thyroid antibodies, then this means that whatever symptoms you’ve been experiencing are unrelated to an autoimmune disorder.

Ways to get tested

There are three main ways to complete a thyroid antibody test. In-home with a DIY kit, in-home with a professional nurse, and in-person at a clinic.

table with different types of home tests and medication

In-home with a DIY kit

An in-home DIY kit can easily be purchased online. This type of thyroid antibody test will require you to prick your finger and collect blood samples on your own. You’ll then package your samples and drop them off at a post office or mailing center. Once the results are available, you’ll easily be able to see them online. Some people aren’t comfortable doing a test on themselves because blood makes them uncomfortable, while others are comfortable with this type of test. At-home thyroid antibody test kits cost about $100 – $150.

Pros

  • Convenient
  • Receive results quickly
  • Easily view results from your phone

Cons

  • A little bit pricey
  • Not everyone is comfortable with collecting blood

In-home with a professional nurse

An in-home thyroid antibody test with a professional nurse is convenient and reliable. This allows you to stay home while getting tested for thyroid antibodies but still offers the reliability of being tested by a professional.

nurse holding a vial with blood

Pros  

  • Reliable
  • Convenient
  • You don’t have to leave your home

Cons

  • It may take longer to receive your result
  • You’ll have to schedule an appointment and be home when the nurse is coming
clinic laboratory

In person at a clinic

To have your thyroid antibodies tested at a clinic, you’ll have to find a clinic that offers this service and schedule your visit. This option requires you to drive to a facility to have your thyroid antibodies tested. Having thyroid antibodies tested at a clinic may be more reliable than testing them yourself, but it may take longer to receive your results. You’ll also benefit from having a doctor review your results rather than being left to interpret them independently.

Pros

  • Reliable results
  • Have results explained to you by your provider
  • It may be covered by insurance

Cons

  • You have to schedule a visit and commute to a location

How much does a thyroid antibody test cost?

The cost of a thyroid antibody test varies depending on your chosen method. Thyroid tests considered medically necessary may even be covered by your health insurance, so look into what your insurance covers before paying out of pocket for a test.

The cost varies depending on the method; ensure that professionally administered tests also come with medical guidance and interpretation of results.

If you think you may be dealing with a thyroid issue, it is important to find the underlying cause. Getting a reliable test is the best way to confirm your diagnosis and proceed with treatment.