Hypothyroidism: Symptoms, Causes, Laboratory Tests, Treatment

Hypothyroidism is a condition characterized by an underactive thyroid gland that fails to produce sufficient thyroid hormones to meet the body's needs. Due to the critical role of thyroid hormones in regulating metabolism, this can lead to various health issues.

Epidemiology of Hypothyroidism

Hypothyroidism is a widespread endocrine disorder affecting millions of people worldwide. Its prevalence varies based on age, sex, geographic location, and iodine intake.

In developed countries, the prevalence of hypothyroidism ranges from 4-10% of the population. The prevalence is often attributed to better screening practices and higher awareness levels. In developing regions, the prevalence can be significantly higher due to iodine deficiency, which remains a significant cause of hypothyroidism globally.

The incidence of hypothyroidism increases with age. It is widespread in older adults, where it can be misdiagnosed due to overlapping symptoms with other age-related conditions. Women are disproportionately affected by hypothyroidism, with an estimated 5-8 times higher risk compared to men. This increased risk is related to autoimmune mechanisms, which are more prevalent in women.

Regions with low iodine levels in the soil and diet have higher rates of hypothyroidism. Iodine is essential for thyroid hormone production, and deficiency can lead to thyroid dysfunction. Exposure to certain environmental toxins and pollutants can interfere with thyroid function, contributing to the development of hypothyroidism.

Symptoms of Hypothyroidism

The symptoms of hypothyroidism can vary widely and often develop slowly, making the condition difficult to diagnose. They result from the body's slowed metabolic processes and can affect multiple organ systems.

Fatigue and Weakness: Persistent tiredness and muscle weakness are hallmark symptoms of hypothyroidism, often leading to reduced physical activity and productivity.
Weight Gain: Unexplained weight gain and difficulty losing weight are common due to a slower metabolic rate.
Cold Intolerance: Due to decreased thermogenesis, individuals with hypothyroidism often feel unusually cold, even in warm environments.
Memory Problems and Concentration Issues: Hypothyroidism can lead to cognitive impairments, including memory lapses and difficulty concentrating.
Depression and Mood Swings: Mood disturbances such as depression, anxiety, and irritability are frequently reported, likely due to hormonal imbalances affecting brain function.
Dry Skin and Hair: Dry, coarse skin and brittle hair are common, as thyroid hormones play a key role in maintaining skin and hair health.
Hair Loss: Diffuse hair loss can occur, which can be distressing for affected individuals.
Bradycardia: A typical slow heart rate reflects decreased cardiac output and metabolism.
Hyperlipidemia: Elevated cholesterol levels are often seen in hypothyroid patients, increasing the risk of cardiovascular disease.
Constipation: Slowed digestive processes can lead to chronic constipation, a common complaint among those with hypothyroidism.
Menstrual Irregularities: Women may experience heavy, irregular periods or amenorrhea, which can impact fertility.
Decreased Libido: Both men and women may suffer from reduced sexual desire.

Causes of Hypothyroidism

Hypothyroidism can result from a variety of causes, which can be broadly categorized into primary, secondary, and tertiary origins.

1. Primary Hypothyroidism

Hashimoto's Thyroiditis: The most common cause of hypothyroidism in developed countries is Hashimoto's thyroiditis, an autoimmune condition where the immune system attacks the thyroid gland.
Iodine Deficiency: Inadequate dietary iodine intake impairs thyroid hormone production.
Medications: Certain medications, such as lithium and amiodarone, can interfere with thyroid function.
Thyroid Surgery and Radioactive Iodine Treatment: Surgical removal of the thyroid gland or treatment with radioactive iodine for hyperthyroidism or thyroid cancer can result in hypothyroidism.

2. Secondary Hypothyroidism

Pituitary Disorders: Conditions affecting the pituitary gland, such as tumors or inflammation, can reduce the secretion of Thyroid-Stimulating Hormone (TSH), leading to hypothyroidism.

3. Tertiary Hypothyroidism

Hypothalamic Disorders: Rarely, dysfunction in the hypothalamus can impair the release of Thyrotropin-Releasing Hormone (TRH), which in turn affects TSH secretion and thyroid function.

4. Transient Hypothyroidism

Postpartum Thyroiditis: Temporary hypothyroidism can occur after childbirth, often resolving spontaneously.
Subacute Thyroiditis: Inflammation of the thyroid gland, typically following a viral infection, can temporarily disrupt thyroid hormone production.

5. Congenital Hypothyroidism

Genetic Factors: Some infants are born with hypothyroidism due to genetic mutations affecting thyroid hormone synthesis.

Hypothyroidism is a multifaceted condition with a diverse array of causes and symptoms. Its widespread prevalence, particularly among women and older adults, underscores the importance of awareness and early diagnosis.

Functional Medicine Root Causes of Hypothyroidism

Functional medicine aims to uncover the underlying imbalances and triggers that contribute to hypothyroidism. Fundamental root causes often explored in functional medicine include:

1. Nutritional Deficiencies

Iodine: Essential for thyroid hormone synthesis, iodine deficiency remains a significant cause of hypothyroidism.
Selenium: Vital for converting T4 to T3, selenium deficiency can impair thyroid function.
Zinc, Magnesium, and Iron are crucial for thyroid hormone metabolism and synthesis.
Vitamin D: Deficiency in vitamin D is linked to autoimmune thyroid disorders and overall immune dysfunction.

2. Autoimmunity

Hashimoto’s Thyroiditis: As an autoimmune disorder, Hashimoto's is a primary cause of hypothyroidism, where the immune system attacks the thyroid gland.
Gut Health: Intestinal permeability ("leaky gut") can trigger autoimmune reactions, contributing to conditions like Hashimoto's thyroiditis.

3. Hormonal Imbalances

Adrenal Dysfunction: Chronic stress and adrenal fatigue can affect thyroid function by disrupting the hypothalamic-pituitary-adrenal (HPA) axis.
Sex Hormones: Imbalances in estrogen and progesterone can influence thyroid hormone levels and function.

4. Environmental Toxins

Heavy Metals: Exposure to heavy metals like mercury and lead can interfere with thyroid function.
Endocrine Disruptors: Chemicals such as BPA, phthalates, and pesticides can disrupt thyroid hormone balance and function.

5. Chronic Infections

Viral and Bacterial Infections: Chronic infections, including Epstein-Barr virus (EBV) and Lyme disease, can impact the immune system and thyroid function.

Functional Medicine Lab Tests for Hypothyroidism

A comprehensive evaluation of thyroid function and related imbalances is essential in functional medicine. Critical lab tests include:

Thyroid Basic Profile
Thyroid Extended Profile
Vitamin D: Assessing levels is crucial for immune function and overall health.
Selenium and Zinc: Deficiencies in these minerals can impact thyroid function.
Ferritin: Measures iron stores, as iron is essential for thyroid hormone synthesis.
Cortisol Levels: Evaluating cortisol through saliva tests can help identify adrenal dysfunction. See AdrenalScan®
Estrogen, Progesterone, Testosterone: Imbalances can impact thyroid health.
Comprehensive Stool Analysis: Identifies dysbiosis, infections, and intestinal permeability. See EnteroScan® Comprehensive
Food Sensitivity Testing: Detects immune reactions to specific foods that may contribute to inflammation and autoimmunity. See Food Intolerance TrophoScan® 200
Genetic Testing for Hypothyroidism and 13 other diseases is included in the Genetic Screening for Endocrine and Genitourinary Diseases, Polygenic Risk Score.

Natural Treatments for Hypothyroidism

Functional medicine emphasizes natural and holistic treatments to support thyroid health and address underlying causes. Key strategies include:

1. Nutritional Interventions

Iodine-rich foods: Sea vegetables, fish, dairy, and iodized salt can help maintain adequate iodine levels.
Selenium Sources: Brazil nuts, fish, and seeds are excellent sources of selenium.
Zinc and Iron: Red meat, poultry, beans, and nuts can help meet zinc and iron requirements.
Vitamin D: Sun exposure and supplementation can help correct deficiencies.

2. Dietary Modifications

Anti-Inflammatory Diet: Emphasizing whole, unprocessed foods and reducing inflammatory foods such as gluten, dairy, and refined sugars.
Gut-Healing Protocols: Incorporating probiotics, prebiotics, and gut-healing nutrients like L-glutamine and bone broth.

3. Stress Management

Mind-Body Techniques: Yoga, meditation, and deep breathing can help reduce stress and support adrenal health.
Adequate Sleep: Ensuring sufficient and quality sleep is crucial for hormonal balance.

4. Detoxification

Reduce Toxin Exposure: Avoiding known endocrine disruptors found in plastics, pesticides, and personal care products.
Support Detox Pathways: Use supplements and foods that support liver detoxification, such as cruciferous vegetables, garlic, and green tea.

5. Supplementation

Adaptogens: Herbs like ashwagandha and rhodiola can support adrenal and thyroid function.
Thyroid Supportive Nutrients: Supplementing with iodine, selenium, zinc, and vitamin D as needed, based on lab results.
Omega-3 Fatty Acids: These are found in fish oil and can help reduce inflammation and support overall health.

6. Addressing Infections

Antimicrobial Treatments: Using natural or medical interventions to address chronic infections that may contribute to thyroid dysfunction.

7. Balancing Hormones

Bioidentical Hormone Therapy: For women with significant hormonal imbalances, bioidentical hormone replacement therapy (BHRT) may be considered.

Functional medicine provides a comprehensive and personalized approach to managing hypothyroidism by addressing root causes, utilizing thorough diagnostic testing, and implementing natural, holistic treatments. This integrative strategy alleviates symptoms and promotes optimal thyroid health and overall well-being. Through nutritional interventions, stress management, detoxification, and targeted supplementation, individuals can achieve better thyroid function and an improved quality of life.

Vasilis J. Sideris
Biologist
Medical Doctor, Biopathologist (Microbiologist)
Certified Functional Medicine Practitioner, CFMP®