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Everything You Need to Know About Thyroid Testing

Medically Approved by Dr. Edward Salko

Table of Contents

Thyroid testing evaluates the function of the thyroid gland and helps detect thyroid disorders. It primarily screens for health issues involving the thyroid gland – a small, butterfly-shaped gland found in the front of the neck. 

Since the thyroid gland releases hormones that control the body’s metabolism, energy levels, and temperature, it’s crucial to undergo a thyroid function test when symptoms of unusual thyroid activities manifest, among other related disorders. Read on to learn what a thyroid test is, how to prepare for one, and tips on ensuring optimum thyroid health. 

What Is Thyroid Testing?

Thyroid testing assesses the health of the thyroid gland. It determines if the thyroid gland produces normal hormone levels and shows underlying tissue damage that impacts function. There are two primary types of thyroid tests: thyroid blood tests and thyroid imaging tests.

Thyroid Blood Tests

Thyroid blood tests can be classified based on the type of thyroid hormone they measure,  specifically, thyroid-stimulating hormone (TSH), triiodothyronine (T3), thyroxine (T4), and thyroid antibodies. 

  • TSH Test: This test determines TSH levels. It is a hormone from the pituitary gland stimulating thyroid gland hormone production.  High TSH levels may suggest hypothyroidism (underactive thyroid), while a low level indicates hyperthyroidism (overactive thyroid).
  • T3 and T4 Tests: These tests measure thyroid hormones T3 and T4 in the blood. Low levels of T3 and T4 indicate hypothyroidism, while high levels indicate hyperthyroidism. To better understand these two, check out our guide on differentiating T3 vs T4 thyroid hormones
  • Thyroid Antibodies Test: This test detects antibodies in the blood that attack the thyroid gland. High levels of thyroid antibodies may indicate an autoimmune disorder such as Hashimoto’s disease or Graves’ disease.

Thyroid Imaging Tests

Imagery technology is used to examine the size, shape, and function of the thyroid gland.

  • Ultrasound: This well-known imaging test produces images of the thyroid gland through high-frequency sound waves. Through an ultrasound, nodules and other abnormalities in the gland may be detected.
  • Thyroid Scan: A thyroid scan uses small amounts of radioactive material to examine the thyroid gland’s function. This test helps identify the cause of hyperthyroidism and check for thyroid nodules.

Who Should Get Thyroid Testing?

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Thyroid testing is often recommended by physicians to people experiencing thyroid disease symptoms, which include: 

  • fatigue or extreme tiredness
  • sensitivity to heat or cold
  • constipation
  • unexplained weight gain or loss
  • sleep disturbances
  • irregular periods
  • dry skin
  • hair loss 

These symptoms may also vary based on the type of thyroid disease and can be narrowed down based on thyroid activities. For example, hypothyroidism may cause fatigue, weight gain, and depression, while weight loss, anxiety, and heart palpitations can be observed among those with hyperthyroidism.

On the other hand, thyroid cancer may show no symptoms early on. But as cancer grows, a lump or swelling will start to develop in the neck, accompanied by difficulty in swallowing and voice hoarseness. The condition is confirmed via imaging tests, among other lab workups. 

Individuals with a family history of thyroid disease and those diagnosed with autoimmune can benefit from thyroid function tests as well. If you’ve undergone radiation therapy or regular exposure to such energy, you should also consider taking thyroid tests. These conditions increase your risk for thyroid dysfunction and can only grow significantly with age. 

Finally, those who plan to lose weight and want to do it right should also look into including a thyroid blood test as part of their weight loss profile lab tests

Thyroid tests are also used to monitor thyroid disorder treatments. Regular thyroid function tests are essential for individuals with thyroid disorders to determine whether treatment is working properly and whether hormone levels are within normal limits.

How to Prepare for Thyroid Testing

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Fasting is typically not required before thyroid testing. However, some healthcare providers may recommend fasting for a few hours before the test to obtain more accurate results. Find out the essential steps when preparing for fasting before your blood test to ensure you’re doing it right. 

Additionally, talk to your healthcare provider before having thyroid testing if you are taking any medications or supplements. Certain medications can interfere with thyroid hormone levels and affect test results.

Understanding Thyroid Gland Dysfunction

Aside from its role in regulating metabolism, body temperature, heart rate, and the production of other hormones, the thyroid gland also influences the brain development of children and mental health issues among adults. Therefore, if problems arise concerning thyroid functions, health issues can easily follow a domino effect. For example, one complication of hypothyroidism is hypertension or increased blood pressure due to high bad cholesterol in the blood. 

And on the subject of hypothyroidism, this condition, along with hyperthyroidism, is considered two of the most common thyroid conditions to watch out for. In fact, many thyroid-related disorders often boil down to irregular thyroid activities, classified as either due to hypothyroidism or hyperthyroidism. This correlation also goes both ways.

Simply put, hypothyroidism is when your thyroid gland has less-than-normal activities, specifically hormone production. On the other hand, hyperthyroidism pertains to an overactive thyroid gland that overproduces hormones, causing an imbalance in the endocrine system. 

Common Causes and Risk Factors for Thyroid Issues

A thyroid issue can be caused by a number of factors. They include radiation therapy, autoimmune disorders, and iodine deficiency. 

Neck and head radiation therapy can also damage the thyroid gland, leading to hypothyroidism. Hence, those who undergo the procedure often take thyroid testing to monitor such impact. 

Autoimmune disorders, such as Hashimoto’s thyroiditis and Graves’ disease, can also cause the immune system to attack the thyroid gland, leading to hypothyroidism or hyperthyroidism.

In the case of iodine deficiency, it primarily impacts the actual hormone production. Iodine is a key mineral in the production of T3 and T4. Obviously, when the thyroid gland can’t produce enough thyroid hormone because of insufficient iodine, hypothyroidism develops.

Pregnancy can also alter thyroid functions due to the higher demand for estrogen and the production of human chorionic gonadotropin (hCG) for fetal development. The risk for the condition increases for women who have pre-existing thyroid problems. Also, there’s a chance that postpartum thyroiditis (inflammation) might develop, but it’s rare. 

Did You Know? An iodine test could be a follow-up test if you were diagnosed with hypothyroidism to trace the condition’s true cause. However, you should secure your doctor’s recommendation before jumping into this test, as other factors may have stood out during the assessment. 

Treatment and Prevention

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The treatment plan for thyroid problems depends on the specific medical condition that has to be addressed. 

For hypothyroidism, hormone replacement and supplements through oral medication can be prescribed. Beyond this, your doctor will also assess the cause of the condition. If it’s iodine deficiency, you’ll be encouraged to increase iodine in your diet. If it’s due to an autoimmune disease, additional treatment will be explored. 

On the other hand, hyperthyroidism can be cured through anti-thyroid medications and medicines that regulate the symptoms. Radiation therapy and surgery are also other options depending on the severity of the condition. 

The same with hypothyroidism. Your doctor will have to uncover the condition’s root cause to completely cure thyroid hyperactivity. 

Although, in various cases, thyroid problem treatment may not be as straightforward, you can supplement the process by taking care of your thyroid gland. The following encompasses tips not just to improve treatment but also to prevent thyroid problems.  

  • Ensure adequate intake of dietary iodine and selenium sources
  • Quit smoking following a proper withdrawal process
  • Avoid endocrine disruptors like perfluorinated chemicals 
  • Keep a healthy diet and avoid high sugary and fatty foods
  • Know your risk of developing thyroid disease

For more ways on how to keep your thyroid healthy, read our guide on ways to improve thyroid function naturally

Frequently Asked Questions

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Does CBC include thyroid testing?

No, because a complete blood count (CBC) only covers the evaluation of blood cells. Thyroid testing is a separate laboratory workup specifically designed to assess TSH and thyroid hormones. 

How can I check my thyroid at home?

Aside from taking note of thyroid disease symptoms, you can physically look for any hints of physical abnormalities by feeling any protrusion or enlargement in your neck. Check your thyroid at home in front of a mirror and see if there are bulges in your lower neck, especially when you swallow or drink water. For men, keep in mind that your thyroid gland is below the Adam’s apple. 

Can I get a thyroid test without a doctor?

It’s possible to take a thyroid test without seeing a doctor first, especially if you’re taking it as part of a general health screening. However, make sure you consult your doctor about the test results instead of self-diagnosing. You can book a thyroid profile test here at Personalabs following four simple steps, from ordering to getting your results. 

The Bottom Line

Thyroid testing reveals any functional problems in your thyroid gland and prevents complications that can impact your metabolism, fertility, and overall wellness. Whether as part of your annual physical exam or a diagnostic measure, communicate any related symptoms and your test results to your doctor to have a better chance of resolving the underlying issues.

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