Medical Review: This content has been reviewed and approved for medical accuracy by Margaret A. Eagan, MD, Board-Certified in Endocrinology and Lifestyle Medicine, and Founder of Rousia.



INTRODUCTION


What is the Function of the Thyroid Gland?

Diagram showing the anatomy and function of the thyroid gland.

Endocrinology is the study of all the hormones produced by the endocrine system. These hormones help control and regulate multiple functions of the body, including energy and metabolism. The major endocrine glands include the thyroid, pancreas, adrenal, pituitary, ovaries, and testes.

The thyroid is a vital, butterfly-shaped gland located at the front of the neck. It plays a critical role in the body's metabolism by producing essential hormones such as thyroxine (T4) and triiodothyronine (T3), which regulate how your body uses energy. Endocrinologists are doctors who specialize in hormone health, including thyroid disorders.

In the U.S., 12% of the population will have a thyroid disorder in their lifetime. 60% of those with thyroid disorder do not know they have it. Women are 5 to 10 times more likely to have thyroid problems than men. One in eight women are likely to have a thyroid imbalance. Thyroid disorder rates also increase with age.

Diagram showing the anatomy and function of the thyroid gland.


Main Thyroid Disorders Explained

Chart illustrating the normal and abnormal levels of thyroid hormones.

Discover the various conditions affecting thyroid health and the importance of thyroid health management:



Chart illustrating the normal and abnormal levels of thyroid hormones.
  • Hypothyroidism: Occurs when the thyroid gland does not produce enough hormones, leading to a slowdown in metabolic processes. Hypothyroidism is typically diagnosed between the ages of 30 and 50. Hashimoto's thyroiditis is a common cause of hypothyroidism.
  • Hyperthyroidism: Arises when the thyroid gland produces too many hormones, speeding up metabolic processes. Hyperthyroidism is typically diagnosed between the ages of 20 and 40. Graves' disease is a common cause of hyperthyroidism.
  • Goiter: An enlargement of the thyroid gland that can occur in hypothyroidism, hyperthyroidism, and a normal-functioning thyroid gland. Goiter may cause visible swelling at the base of the neck.
  • Multinodular Goiter: The presence of multiple nodules in an enlarged thyroid gland (goiter), which can occur in the presence of hypothyroidism, hyperthyroidism, and a normal-functioning thyroid gland.
  • Thyroiditis: Inflammation of the thyroid, often triggered by an autoimmune response. Types of thyroiditis include subacute thyroiditis, postpartum thyroiditis, and silent thyroiditis.
  • Thyroid Nodules: Nodules within a normal-size thyroid gland. While most nodules are benign, some can be malignant. While most nodules are benign, some can be malignant. Any visible nodule needs to be evaluated by a healthcare provider.
  • Thyroid Cancer: Though rare, this condition involves malignant growths within the thyroid gland. Thyroid cancer may present as a lump or nodule in the neck.

Thyroid disorders, such as hypothyroidism, hyperthyroidism, and thyroid cancer, often run in families, indicating a genetic component to these conditions. By being aware of your family's medical history, you can take proactive steps in monitoring your thyroid function and seeking early medical intervention if needed. Genetic testing can also identify specific mutations and biomarkers that influence thyroid function, enabling personalized treatment plans tailored to your unique genetic makeup. Prioritizing knowledge of family history and genetics can lead to better prevention, early detection, and effective management of thyroid disorders.


IDENTIFYING SYMPTOMS OF THYROID DISORDERS

Diagram comparing symptoms of hyperthyroidism and hypothyroidism.

Common thyroid symptoms for different thyroid disorders include:

  • Hypothyroidism (Underactive Thyroid)
    • Fatigue and Weakness: Reduced levels of thyroid hormones can decrease overall energy production in the body, leading to fatigue and general weakness.
    • Weight Gain or Difficulty Losing Weight: Lowered thyroid hormone levels can slow down the metabolic rate, making it difficult to lose weight and easy to gain it.
    • Dry Skin and Hair: Hypothyroidism can reduce sweat and oil production in the skin, leading to dry, flaky skin and dry, brittle hair.
    • Cold Intolerance: With decreased metabolism, the body generates less heat, which can make a person with hypothyroidism more sensitive to cold.
    • Constipation: Reduced hormone production can slow down the digestive process, leading to constipation.
    • Depression or Mood Changes: Thyroid hormones have a significant impact on brain chemistry. Low levels can lead to mood disturbances, including depression.
    • Cardiovascular changes: Decrease in heart rate(bradycardia) and an increase in diastolic blood pressure greater than the increase in systolic blood pressure.
    • Neurological changes: Hypothyroidism may present as a slowing down of thought processes such as a decrease in memory(especially verbal), concentration and the ability to make decisions. Other changes include a delayed response in the reflex relaxation phase(Woltman’s sign).
    • Irregular Periods: Hypothyroidism can disrupt reproductive hormones, causing irregular menstrual cycles. Women may experience heavier, longer, or more frequent periods, or lighter and less frequent menstruation.
    • Infertility: Low thyroid hormone levels can interfere with ovulation, making conception more difficult. This hormone imbalance can contribute to challenges in achieving and maintaining pregnancy.
    Diagram comparing symptoms of hyperthyroidism and hypothyroidism.
  • Hyperthyroidism (Overactive Thyroid)
    • Fatigue and Muscle Weakness: Despite increased energy levels, the breakdown of muscle proteins and increased energy demands can result in fatigue and muscle weakness.
    • Weight Loss: Increased metabolism caused by excess thyroid hormones can lead to significant weight loss despite normal or increased appetite.
    • Skin and hair changes: hyperthyroidism may cause hives, skin sensitivity, itchiness, thinning hair
    • Heat Intolerance and Over Sweating: Hyperthyroidism can cause the body to generate more heat and increase sweat production to cool down.
    • Bowel changes: Hyperthyroidism may cause hypermotility of the GI tract resulting in frequent bowel movements
    • Nervousness, Anxiety, or Irritability: Excess thyroid hormones can stimulate the nervous system, leading to feelings of anxiety or irritability.
    • Cardiovascular changes: Excess thyroid hormones causes an increased heart rate and heart contraction resulting in palpitations and increased blood pressure
    • Neurological changes: Hyperthyrodism may cause memory loss, brain fog, decrease in executive functions and attention deficit. Other symptoms may include fine shaking, especially in the hands, due to heightened stimulation of the nervous system.
    • Irregular Periods: Hyperthyroidism can disrupt reproductive hormones, causing irregular menstrual cycles. Women may experience heavier, longer, or more frequent periods, or lighter and less frequent menstruation.
    • Infertility: Low thyroid hormone levels can interfere with ovulation, making conception more difficult. This hormone imbalance can contribute to challenges in achieving and maintaining pregnancy.
  • Thyroid Nodules or Goiter
    • Visible Swelling at the Base of the Neck: A most common sign, the swelling can vary in size from barely noticeable to very large and obvious.
    • Feeling of Tightness in the Throat: As the thyroid gland enlarges, it can press against other structures in the throat, causing a sensation of tightness or discomfort.
    • Hoarseness or Voice Changes: If the growth impinges on the recurrent laryngeal nerve (which controls the vocal cords), it can cause changes in the voice, including hoarseness.
    • Difficulty Swallowing or Breathing: Large nodules may compress the esophagus or trachea respectively, leading to difficulty swallowing or breathing. These are more severe symptoms and usually occur when the nodules are significantly enlarged.

KNOWING YOU HAVE A THYROID DISORDER


Our goal is to empower you with the knowledge to take control of your thyroid health and advocate for your well-being in a proactive and informed manner.

Recognize the Symptoms: Awareness of the above symptoms is the first step. If a person experiences a combination of these symptoms persistently(for at least three months), it might indicate a thyroid problem.

  • Symptom Checker: Rousia offers an interactive symptom checker that you might find helpful.
  • Screening Questionnaires: Some healthcare providers and telehealth services use screening questionnaires to capture symptoms that might suggest a thyroid problem before the patient even sees the provider.

Self-Evaluation: Checking the neck for any visible swelling or irregularities can be an early self-test. This involves looking in the mirror, tipping the chin up slightly, taking a sip of water, and swallowing to see if any bulges or protrusions appear in the lower neck area as the thyroid gland moves during swallowing.

Consultation with a Healthcare Provider: If symptoms persist for at least three months or a nodule is seen or felt, consulting a healthcare provider is essential. Telehealth platforms can be an initial point of contact where patients describe their symptoms and receive advice on necessary tests.

Thyroid Function Tests: Perform thyroid function tests at home, which include measuring levels of Thyroid Stimulating Hormone (TSH), Free Thyroxine (T4), Triiodothyronine (T3), and Thyroid Peroxidase Antibodies (TPO). These tests can typically be done through a simple at-home dry blood test.

Further Evaluation: Depending on the test results and symptoms, further evaluation might include an ultrasound of the thyroid if nodules or enlargement are suspected. This step requires an in-person visit to a healthcare facility.

Regular Monitoring: If diagnosed with a thyroid condition, regular monitoring of thyroid hormone levels is necessary to manage the condition effectively.

ESSENTIAL THYROID FUNCTION TESTS


Graphic explaining common terminology used in thyroid testing.

In the regulation of thyroid hormones, the hypothalamus in the brain plays a foundational role by producing Thyrotropin-Releasing Hormone (TRH). TRH signals the pituitary gland to release Thyroid Stimulating Hormone (TSH), which in turn stimulates the thyroid gland to produce thyroxine (T4) and triiodothyronine (T3). This process is essential for maintaining the body's metabolic rate, heart function, and more.

Thyroid function tests are essential tools used to diagnose and manage thyroid disorders effectively. These tests measure levels of various hormones in your blood that are crucial for proper thyroid function. Here is a detailed explanation for each test and an example to elucidate it:

Graphic explaining common terminology used in thyroid testing.
  • TSH Test (Thyroid-Stimulating Hormone)
    • Detailed Explanation: The TSH test is often the first step in thyroid evaluation. Thyroid-stimulating hormone, produced by the pituitary gland, regulates the production of thyroid hormones. If your TSH levels are high, it usually indicates that your thyroid gland is not making enough hormones (hypothyroidism), prompting your pituitary to produce more TSH to stimulate the thyroid gland to produce more thyroid hormone. Conversely, low TSH levels can suggest hyperthyroidism, where the thyroid gland produces too much hormone, reducing the need for pituitary stimulation.
    • Example: Imagine your body as a factory where the thyroid gland consists of the workers. Thyroid hormones are the product, and the manager is the pituitary gland.
      • Hypothyroidism: When production is at a standstill, the manager increases calls( increase TSH) to the workers to increase production, but there are no materials to make the product(low T4 and sometimes low T3). This is primary hypothyroidism; the thyroid gland has run out of material to make thyroid hormones. The pituitary gland senses this low production and sends a signal to the thyroid (high TSH level) to increase production of thyroid hormones. The thyroid gland is unable to respond due to lack of materials( low T4 and sometimes low T3). TSH (signal) levels will be high. T4 and sometimes T3levels (product) levels will be low.
      • Hyperthyroidism: When product is flooding the market (high T4 levels and sometimes high T3 levels), the manager stops calls (decrease TSH) to the workers to decrease production. This is primary hyperthyroidism; the thyroid gland operates on its own, making thyroid hormones and releasing them into the system. The pituitary gland senses the high levels of thyroid hormones and decreases its signal (TSH) to the thyroid gland. The thyroid gland, operating on its own, does not respond to the decrease in the signal. TSH (signal) levels will be low. T4 and sometimes T3levels (product) levels will be high.
  • T4 Tests (Thyroxine Levels)
    • Detailed Explanation: These tests measure thyroxine levels in the blood. Total T4 includes both bound and free thyroxine, while Free T4 measures thyroxine that is not bound to proteins and is available for your body to use. The balance of free and total T4 provides insight into how the thyroid is functioning and how it's interacting with other body systems.
    • Example: Consider thyroxine as money. The money in your bank account plus the money in your wallet is like the Total T4. Money that you have in your wallet is Free T4.
  • T3 Tests (Triiodothyronine)
    • Detailed Explanation: Triiodothyronine tests are additional tests that might be ordered to further assess thyroid function, particularly in cases where more information is needed beyond TSH and T4 levels. Total T3 includes both bound and free triiodothyronine, while Free T3 measures triiodothyronine that is not bound to proteins and is available for your body to use.
    • Example: Consider triiodothyronine as money. The money in your bank account plus the money in your wallet is like the Total T3. Money that you have in your wallet is Free T3.
  • Thyroid Antibody Tests
    • Detailed Explanation: These tests check for the presence of antibodies against thyroid-specific proteins, indicating autoimmune thyroid diseases like Hashimoto's thyroiditis or Graves' disease. These antibodies are inherited and can alter thyroid function, leading to chronic thyroid health issues.
    • Example: Imagine your immune system as a home security system. In autoimmune disorders, the security system mistakenly identifies some of the home’s components (thyroid cells) as intruders, leading to an attack on those components.

Understanding these key tests for assessing thyroid health can help you understand your thyroid health management journey. Here is a summary of their purpose and when they are ordered:

  • TSH Test (Thyroid-Stimulating Hormone)
    • Purpose: Measures TSH levels in the blood to evaluate thyroid function. TSH is produced by the pituitary gland and is responsible for regulating the production of hormones by the thyroid gland.
    • When Ordered: Typically, the first test to assess for potential thyroid dysfunction. Elevated levels may indicate hypothyroidism, while lower levels could suggest hyperthyroidism.
  • T4 Tests (Thyroxine)
    • Purpose: Determines the levels of total or unbound thyroxine in the blood. Thyroxine is a major hormone produced by the thyroid gland.
    • When Ordered: Conducted following a TSH test to further evaluate thyroid function.
  • T3 Tests (Triiodothyronine)
    • Purpose: Measures the levels of triiodothyronine in the blood, helpful in diagnosing hyperthyroidism.
    • When Ordered: Typically ordered when T4 and TSH tests do not fully explain the suspected thyroid dysfunction.
  • Thyroid Antibody Tests
    • Purpose: Identifies the presence of antibodies against thyroid peroxidase (TPO) and thyroglobulin, suggesting autoimmune thyroid conditions.
    • When Ordered: Recommended if autoimmune disorders like Hashimoto's thyroiditis or Graves' disease are suspected.

UNDERSTANDING THYROID TEST TERMINOLOGY


Thyroid Function Tests (TFTs): This term is specific and widely recognized within medical literature, referring to the tests that evaluate the function of the thyroid gland by measuring hormone levels.

Even if only one test is ordered to assess the thyroid, the term"thyroid function tests" (TFTs) is still commonly used in both singular and plural contexts. This usage persists because the term has become standardized and is widely recognized in medical practice for referring to any test that assesses thyroid hormone levels, whether it involves multiple tests or a single test.

AT-HOME TESTING: DRY BLOOD TESTS


Dry blood spot (DBS) testing offers a less invasive method for obtaining blood samples through a finger prick, facilitating thyroid-related tests at home.

Thyroid Antibody Tests: Some labs have developed methods to evaluate thyroid antibodies using DBS samples. However, the feasibility depends on test sensitivity, available technology, and antibody stability.

NAVIGATING COMMON THYROID CONDITIONS AND THEIR MANAGEMENT


Here are some guidelines on how common thyroid issues are diagnosed and managed, emphasizing the blend of remote and in-person care options:

  • Hypothyroidism
    • Remote Testing Options: Initial TSH and T4 testing can be conducted at home, with follow-up via telehealth.
    • In-Person Requirements: Necessary for comprehensive physical exams if symptoms persist despite normal test results.
  • Hyperthyroidism
    • Remote Initial Testing: Basic TSH, T3, and T4 tests can be handled remotely.
    • Specialized In-Person Testing: Specialized radiological tests for definitive diagnosis.
  • Thyroiditis
    • Remote Monitoring Feasibility: Blood tests can be initially done remotely.
    • In-Person Requirements: Specialized radiological tests for definitive diagnosis.
  • Thyroid Nodules
    • Remote Monitoring Feasibility: Blood tests can be initially done remotely.
    • In-Person Requirements: It is imperative to be evaluated by a healthcare provider.

EMPOWERING YOUR THYROID HEALTH JOURNEY


Here are some tools and information to recognize symptoms and understand when to seek medical advice or further evaluation:

  • Symptom Awareness and Self-Checks: Educate yourself on how to identify signs of thyroid issues and perform initial self-assessments.
  • Navigating Through Telehealth and In-Person Care: Learn to use convenient telehealth services effectively, while understanding the importance of in-person assessments when necessary.

Physical examination of the thyroid includes palpating the gland in the neck to check for enlargement, nodules, or tenderness. These tests cannot be adequately performed remotely and is essential for diagnosing conditions like thyroiditis or thyroid nodules.

Here are instances where in-person visits are necessary:

  • Suspected thyroid nodules or goiter: Requires ultrasound and possible biopsy.
  • Complex cases: Where symptoms and blood tests do not align, or if there is a history of thyroid cancer or radiation exposure.
  • Procedure-based diagnostics: Such as fine needle aspiration or radioactive iodine studies.

CONCLUSION


Understanding your thyroid health is an essential step towards maintaining your overall well-being. As we have explored, the thyroid gland plays a critical role in regulating numerous bodily functions through hormone production. Recognizing the symptoms of thyroid disorders and knowing the available diagnostic tests empowers you to take charge of your health. We encourage you to use the knowledge gained from this guide to engage actively with healthcare providers and take informed steps towards optimizing your thyroid health. In Thyroid Health 102, we delve into management of thyroid health.


Frequently Asked Questions
1

What is the thyroid gland and what does it do?

The thyroid gland is a small, butterfly-shaped organ located at the base of your neck. It produces thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3), which regulate the body’s metabolism, affecting everything from your heart rate to how quickly you burn calories.

2

How do I know if I have a thyroid problem?

3

What are the most common thyroid function tests?

4

Can thyroid issues be treated from home?

5

Are thyroid health problems common?

6

What can trigger thyroid health issues?

7

How can I check my thyroid at home?

8

When should I see a specialist for my thyroid?

9

Can thyroid conditions be prevented?

10

What lifestyle changes can help manage thyroid health?