Hypothyroidism

Causes:

Hypothyroidism can result from various factors, often leading to insufficient thyroid hormone production:

• Hashimoto’s Thyroiditis: This is the most common cause of hypothyroidism. It’s an autoimmune disorder where the immune system mistakenly attacks and gradually destroys the thyroid gland.
• Thyroiditis: Inflammation of the thyroid gland can temporarily cause hypothyroidism. This includes subacute thyroiditis (often after a viral infection), postpartum thyroiditis (after childbirth), or silent thyroiditis.
• Treatment for Hyperthyroidism: Individuals who have been treated for an overactive thyroid (hyperthyroidism) with radioactive iodine therapy or surgical removal of the thyroid gland (thyroidectomy) often develop permanent hypothyroidism.
• Iodine Deficiency: Iodine is essential for thyroid hormone production. While less common in regions with iodized salt, a severe lack of dietary iodine can lead to hypothyroidism.
• Certain Medications: Some drugs can interfere with thyroid hormone production or function, including:
  • Lithium (used for bipolar disorder)
  • Amiodarone (a heart medication)
  • Interferon alpha
  • Some cancer medications
• Congenital Hypothyroidism: Some babies are born with an underdeveloped or absent thyroid gland.
• Pituitary Disorder: Rarely, a problem with the pituitary gland (which produces TSH, thyroid-stimulating hormone) can lead to the thyroid not being stimulated enough to produce hormones.
• Radiation Therapy: Radiation to the neck or head for other cancers can damage the thyroid gland.

Symptoms:

The symptoms of hypothyroidism often develop slowly over time and can be subtle, making them easy to overlook or attribute to aging. They are generally related to a slowed metabolism:

• Fatigue and sluggishness: Feeling tired and lacking energy, even after adequate sleep.
• Weight gain: Despite no changes in diet or activity levels.
• Increased sensitivity to cold: Feeling cold even in warm environments.
• Constipation.
• Dry skin and brittle nails.
• Thinning hair or hair loss.
• Muscle aches, tenderness, and stiffness.
• Joint pain and swelling.
• Depression.
• Impaired memory and concentration (“brain fog”).
• Slowed heart rate (bradycardia).
• Heavy or irregular menstrual periods in women.
• Hoarseness.
• Enlarged thyroid gland (goiter): A swelling at the base of the neck, though not always present.

Diagnosis:

Hypothyroidism is diagnosed through a physical examination, review of symptoms, and blood tests to measure thyroid hormone levels.

• Medical History and Physical Exam: The doctor will ask about your symptoms, family history, and conduct a physical exam, checking your pulse, examining your neck for an enlarged thyroid, and looking for dry skin or other signs.
• Blood Tests:
  • Thyroid-Stimulating Hormone (TSH): This is the most important test. In hypothyroidism, TSH levels are typically elevated (because the pituitary gland produces more TSH in an attempt to stimulate the underactive thyroid).
  • Thyroxine (T4): Levels of this thyroid hormone will be low in hypothyroidism.
  • Thyroid peroxidase (TPO) antibodies: These antibody tests can help diagnose Hashimoto’s thyroiditis.

• Thyroid Ultrasound: May be used to visualize the thyroid gland and identify any nodules or structural abnormalities, though not typically for routine diagnosis of hypothyroidism.

Treatment:

Hypothyroidism is a lifelong condition that is managed by replacing the missing thyroid hormone.

• Thyroid Hormone Replacement Medication:
  • Levothyroxine (Synthroid, Levoxyl, etc.): This synthetic form of thyroxine (T4) is the standard treatment. It is taken orally, usually once daily on an empty stomach.
  • The dosage is carefully adjusted based on TSH levels to restore them to a normal range. It can take several weeks for symptoms to improve after starting medication or adjusting the dose.

• Regular Monitoring:
  • Blood tests (TSH levels) are regularly performed to ensure the medication dosage is correct.
  • Follow-up appointments with your doctor are essential to monitor symptoms and adjust treatment as needed.
• Dietary Considerations:
  • Avoid taking levothyroxine with calcium, iron supplements, or certain foods (e.g., soy products, high-fiber foods) as they can interfere with absorption. It’s best to take it at least 30-60 minutes before breakfast.
  • While iodine deficiency is a cause, excessive iodine intake from supplements should be avoided, as it can sometimes worsen autoimmune thyroid conditions.

With proper diagnosis and consistent treatment, most people with hypothyroidism can effectively manage their condition and lead normal, healthy lives.