by Stephen Luther, M.D.
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The thyroid is often hailed as a ruler of our endocrine system, a network of organs and glands specializing in hormone production. Our thyroid maintains order by expertly regulating our body’s physiological and biological demands with appropriate hormones. This small yet powerful gland is essential for hormonal homeostasis for our metabolism, growth, sexual function, reproduction, and other bodily functions.
Unfortunately, thyroid disease can significantly hinder the overall quality of life and peace associated with good health in approximately 40 million Americans, or 12% of the U.S. population. Symptoms of thyroid disease can begin as early as age 12 and progress gradually or rapidly in severity throughout life.
Prevention, awareness, regular health exams, and, if necessary, treatment are the foundation of Symbios. Because thyroid hormone imbalances are preventable and treatable, we encourage you to learn how your body’s reaction to stimulation, nutrients, and mood can help identify possible warning signs of thyroid disorders.
Understanding the Thyroid’s Functions and Terms
The thyroid is a butterfly-shaped gland in the inferior (lower) and anterior (front) neck. This endocrine gland consists of two lobes (right and left) connected by a thin piece of tissue called the isthmus. It wraps around the trachea (windpipe) and sits below the larynx (voice box).
The thyroid gland produces hormones, which serve as chemical messengers that trigger enzymatic responses due to continuous changes throughout our body. These hormones regulate various bodily functions, particularly metabolism, growth, and development.
The thyroid produces two vital hormones, T3 (triiodothyronine) and T4 (thyroxine), and the hormone calcitonin.
T3 (Triiodothyronine)
- Production: Although T3 makes up only about 20% of the thyroid hormones produced by the thyroid gland, it is the more potent and active hormone. T3 is primarily generated from T4 in peripheral tissues (liver and kidneys).
- Function: T3 influences the rate at which your cells work, affecting everything from heart rate and body temperature to converting food into energy, described in the following physiological processes:
- Cardiac Output and Stroke Volume: The active thyroid hormone, T3, increases calcium levels inside heart muscle cells, boosting the heart’s contractility and efficiency. It provides adequate or increased blood volume while reducing vascular resistance, which can lower blood pressure by activating the renin-angiotensin-aldosterone system (RAAS).
- Basal Metabolic Rate (BMR): T3 is the primary regulator of metabolism. It increases heat and oxygen production, triggering thermogenesis. This process activates glycogenolysis (breaking down glycogen into glucose), gluconeogenesis (creating glucose from non-carbohydrate sources), and the uptake of fatty acids, providing the body with sustained energy.
- Nervous System Stimulation: T3 stimulates the nervous system, helping you stay more alert and responsive to external stimuli. It also enhances reflexes in the peripheral nervous system, supports brain development, boosts cognitive function, and improves mood.
- Reproductive Health: T3 significantly impacts sexual function and reproduction by regulating the bioavailability of sex hormones. In men, it helps maintain erections and supports normal levels of sex hormone-binding globulin. In women, T3 increases luteinizing hormone levels, which enhance sexual desire and support ovarian functions.
T4 (Thyroxine)
- Production: The thyroid produces T4 and circulates it in the bloodstream. While T4 makes up about 80% of all thyroid hormones, it is less active and primarily serves as a precursor to T3.
- Function: T4 is converted into the more active T3 within cells, particularly in the liver and kidneys. While T4 has some metabolic activity, its primary role is ensuring an adequate supply of T3.
Regulation of T3 and T4
Thyroid-stimulating hormone (TSH) is a glycoprotein hormone produced and released by the anterior pituitary gland at the brain’s base. It stimulates the thyroid gland to produce and secrete T3 and T4. The hypothalamus, another part of the brain, controls the release of TSH through a hormone called Thyrotropin-Releasing Hormone (TRH).
- Calcitonin: This hormone helps regulate calcium levels in the blood by lowering them when too high. While produced alongside T3 and T4 in the thyroid, its role is less prominent.
Understanding Thyroid Disease
Thyroid disease is a broad term for all thyroid disorders, which include specific types of dysfunctions or abnormalities within the thyroid gland, including hypothyroidism (underactive thyroid), hyperthyroidism (overactive thyroid), and goiter (enlarged thyroid).
The regulation and balance of thyroid hormones are crucial for overall wellness. While fluctuations in these hormones are standard, persistent deviations can signal abnormalities in the endocrine system and vital organs or indicate autoimmune disorders and nutrient deficiencies. Normal ranges for thyroid hormones are as follows: Thyroid-Stimulating Hormone (TSH) should be between 0.4-4 mU/L, T4 should be between 5.0-12.0 µg/dL, and T3 should be between 80-220 ng/dL. Thyroid hormone levels are the first step in screening for thyroid health. Further testing of T3 and T4 levels is recommended if abnormalities are detected. Persistent deviations can lead to various thyroid disorders:
- Hypothyroidism (Underactive Thyroid) is characterized by elevated TSH levels and reduced T3 and T4 levels. Sensing low T3 and T4, the pituitary gland produces excess TSH to stimulate the thyroid. Symptoms include weight gain, slowed speech and movement, dry skin, bradycardia, and pericardial effusion. TSH levels are typically between 4-10 mU/L.
- Hyperthyroidism (Overactive Thyroid) occurs when the thyroid produces excessive amounts of T3 and T4, leading to suppressed TSH secretion. Symptoms include weight loss, fatigue, heat intolerance, and changes in skin texture. TSH levels are typically between 0 and 0.4 mU/L.
- Hashimoto’s Disease is an autoimmune disorder also known as chronic lymphocytic thyroiditis. It damages or destroys thyroid cells through immune processes, usually causing hypothyroidism. It affects about 5% of the U.S. population and is more common in women. Symptoms and hormone levels are like those of hypothyroidism.
- Metabolic Syndrome (MetS) is a complex condition involving high blood pressure, stroke, type 2 diabetes, and high body fat. It affects thyroid function, particularly metabolism and energy, increasing the risk of cardiovascular disease. MetS is prevalent in about 30% of the U.S. population and is more common in women. TSH levels are typically between 0.25 and 5 mU/L.
Treatments, Lab Tests, and Solutions
The thyroid produces only 10% to 20% of the total T3 in the bloodstream. Hypothyroidism can result from other endocrine system factors or nutrient deficiencies.
Symbios Lab
Symbios Lab offers highly skilled laboratory technologists and experienced phlebotomists, providing outstanding lab services with efficient result times to help individuals pinpoint biological disorders and achieve optimal solutions. We offer affordable prices for labs not covered by your insurance plan. Our services include:
- Thyroid Function Tests: Thyroid Stimulating Hormone (TSH); Free T4 and free T3 levels.
- Comprehensive Metabolic Panels: Blood tests to analyze chemical balances and metabolic rates.
- Hemoglobin A1C (HbA1c) Test: Measures blood sugar/glucose levels to check for imbalances.
- Glucose Tolerance Testing: Measures the body’s ability to tolerate and metabolize glucose.
- Pathology Test: Uses urine, blood, and other bodily fluids to detect potential threats at the intracellular level.
Symbios Nutrition
Nutrition is the cornerstone of cellular health and metabolic processes. Our nutritional specialists create nutrient-rich plans tailored to individual needs that address potential deficits that may reduce wellness. Understanding the biochemical science behind nutrient-dense food groups and the benefits of fats and proteins is vital for sustaining a healthy lifestyle. Vitamins and minerals like selenium and iodine are essential for thyroid function and metabolic rates.
Achieving an Optimal Lifestyle
Thyroid disease may pose concerns for your health and can increase the risk of other health-related diseases and disorders. If you have questions, are experiencing symptoms, have a hereditary disposition for metabolic-related issues, or are interested in lab testing, Symbios offers personal, high-quality care for your complete wellness today and tomorrow.
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