What are the symptoms and treatment options for hyperthyroidism?

Symptoms and Treatment of Hyperthyroidism

Hyperthyroidism is characterized by tremors, nervousness, insomnia, excessive sweating, heat intolerance, tachycardia, hypertension, and goiter, with treatment options including beta-blockers, antithyroid medications, radioactive iodine therapy, or surgery depending on the cause and severity. 1

Common Symptoms

• Cardiovascular symptoms: Tachycardia, hypertension, palpitations, decreased systemic vascular resistance, increased cardiac output, and potential pulmonary artery hypertension 1, 2
• Neurological symptoms: Tremors, nervousness, anxiety, hyperactivity, and insomnia 1
• Dermatological symptoms: Excessive sweating, heat intolerance, and hair loss 1
• Gastrointestinal symptoms: Diarrhea, unintentional weight loss despite increased appetite 3
• Physical findings: Goiter (enlarged thyroid gland), exophthalmos (bulging eyes) in Graves' disease 3
• Rare but serious manifestations: Heart failure in severe, long-standing cases, particularly with persistent tachycardia or rapid atrial fibrillation 4, 2

Diagnosis

• Diagnosis is confirmed by biochemical tests showing low TSH and high free T4 or T3 levels 3, 5
• Etiology can be established based on clinical presentation, thyroid function tests, and thyrotropin-receptor antibody status 3
• Thyroid scintigraphy is recommended if thyroid nodules are present or the etiology is unclear 3

Treatment Options

First-Line Approach

• Beta-blockers (such as atenolol or propranolol) should be initiated promptly to control heart rate, reduce tremors, and mitigate cardiovascular complications 1, 2
  • These provide rapid improvement in cardiac and neurological symptoms while definitive treatment takes effect 2
  • The goal is to lower heart rate to nearly normal, improving tachycardia-mediated ventricular dysfunction 2

Definitive Treatment Options

1. Antithyroid medications:

   • Thionamides such as methimazole or propylthiouracil (PTU) 2, 6
   • PTU is indicated for patients with Graves' disease or toxic multinodular goiter who are intolerant of methimazole 6
   • PTU can also be used to ameliorate symptoms in preparation for thyroidectomy or radioactive iodine therapy 6
   • Treatment duration is typically 12-18 months for Graves' disease, with approximately 50% recurrence rate 5
   • Long-term treatment (5-10 years) is associated with fewer recurrences (15%) 5

2. Radioactive iodine therapy:

   • Most widely used treatment in the United States 7
   • Well-tolerated with the main long-term risk being radioiodine-induced hypothyroidism 8
   • Should be avoided in pregnancy, during lactation, and in children 8
   • Treatment of choice for toxic nodular goiter 8
   • May cause deterioration in Graves' ophthalmopathy 8

3. Surgical thyroidectomy:

   • Has specific but limited roles in hyperthyroidism treatment 8
   • Primarily indicated when there is a large goiter causing compression symptoms 8
   • Also considered when radioactive iodine is refused or contraindicated 8

Special Considerations

• Pregnancy: Hyperthyroidism increases the risk of severe preeclampsia, preterm delivery, and heart failure 1

  • PTU may be preferred in the first trimester, with consideration of switching to methimazole for the second and third trimesters 6

• Cardiovascular complications: Cardiovascular complications are the chief cause of death after treatment of hyperthyroidism, especially in patients over 50 years 4, 2

• Liver function: PTU can cause severe liver problems including liver failure requiring transplantation or resulting in death 6

  • Patients should be monitored for symptoms of hepatic dysfunction (anorexia, pruritus, jaundice, etc.) 6

• Blood disorders: Low white blood cell counts can occur within the first 3 months of treatment with antithyroid drugs 6

  • Patients should report symptoms such as fever, sore throat, or general malaise 6

• Thyroid storm: A rare but life-threatening emergency that can occur in untreated hyperthyroidism 1

Treatment Algorithm

1. Start with beta-blockers to control symptoms
2. Choose definitive treatment based on:
   • For Graves' disease: Antithyroid drugs (first-line), radioactive iodine, or surgery
   • For toxic nodular goiter: Radioactive iodine or surgery (antithyroid drugs have high relapse rates) 5, 9
   • For thyroiditis: Supportive care, as it's usually self-limiting 5