Thyroid Gland

The thyroid gland is found in the neck, below the thyroid cartilage (laryngeal prominence or Adam’s apple) and is responsible for producing actual thyroid hormones from follicular cells that control our energy usage and metabolism

The two main hormones produced from follicular cells are Thyroxine (T4) and Triiodothyronine (T3).  Both T3 and T4 require iodine and tyrosine.

Thyroid hormone (T3, T4) is production is stimulated and controlled by another hormone in the Anterior Pituitary called Thyroid-stimulating hormone (TSH); TSH in turn is stimulated by Thyrotropin-Releasing Hormone (TRH) which is made in the Hypothalamus.

Most common problems associated with this gland include

  • Overproduction of thyroid hormone (HYPERTHYROIDISM)
    • Symptoms
      • Heat intolerance, increased sweating, weight loss with increased appetite, anxiety, irritability, palpitations (heart racing), oligomenorrhea (abnormal menses), increased stool frequency, shortness of breath, fatigue, weakness, double vision, dry-irritated eyes, tremors, bulging eyes, warm/moist skin, hair loss, paralysis (mostly in Asian population)
    • Causes:
      • Grave’s disease (Autoimmune)
      • Toxic multinodular goiter or Toxic Adenoma
      • Postpartum (painless) thyroiditis
      • Subacute (infectious) thyroiditis
      • Iodine excess (medication, iodinated contrast)
      • Factitious (ingestion of thyroid hormone unknowingly in food products)
      • Ectopic thyroid tissue (struma ovarii)
      • Chorionic gonadotropin-induced (choriocarcinoma, hydatidiform mole)
      • TSH-secreting pituitary adenoma 
    • Treatment (where clinically indicated):
      • Anti-thyroidal drugs (Methimazole “MMZ”, Propylthiouracil  “PTU”)
      • Radioactive Iodine-131
      • Surgery
  • Underproduction of thyroid hormone (HYPOTHYROIDISM)
    • Symptoms
      • Cold intolerance, lethargy, fatigue, weight gain, dry skin, hair loss, constipation, muscle pain, arthritis (joint swelling), menorrhagia (abnormally heavy and prolonged menstrual bleeding), hoarseness, facial or eye puffiness, dizziness (bradycardia), poor memory (dementia), swelling (non pitting), carpal tunnel syndrome
    • Causes
      • Chronic lymphocytic (Hashimotos’) thyroiditis
      • Radioactive iodine treatment or external neck radiation; radiation exposure
      • Thyroidectomy
      • Transient (recovery from illness)
      • Drugs (used to treat Hyperthyroidism)
      • Severe iodine deficiency
      • Congenital hypothyroidism
      • Secondary (central) hypothyroidism from pituitary or hypothalamic disease
    • Treatment
      • Levothyroxine
        • Drug absorption limited if also taken with
          • Calcium or Iron supplements, Cholestyramine, Sucralfate, and Aluminum hydroxide
        • Drug metabolized faster if taken
          • Estrogen, Rifampin, some Anti-Seizure drugs, and some Anti-Cancer drugs


Disclaimer: This page is intended for general information and does not substitute for medical recommendations from your health care provider.