What are the symptoms and treatment options for hyperthyroidism?

Hyperthyroidism Symptoms and Treatment

Hyperthyroidism is characterized by tremors, nervousness, insomnia, excessive sweating, heat intolerance, tachycardia, hypertension, and goiter, and treatment options include beta-blockers for symptom relief, antithyroid medications, radioactive iodine ablation, or surgery depending on the cause and severity. 1, 2

Common Symptoms of Hyperthyroidism

Physical Symptoms

• Tremors and nervousness 1
• Excessive sweating and heat intolerance 1, 3
• Unintentional weight loss despite normal or increased appetite 2
• Tachycardia and palpitations 1, 3
• Hypertension 1
• Goiter (enlarged thyroid gland) 1
• Diarrhea or increased bowel movements 2
• Hair loss 1

Neuropsychiatric Symptoms

• Anxiety and nervousness 1, 4
• Insomnia 1
• Fatigue 3
• Hyperactivity 1

Ocular Symptoms (particularly in Graves' disease)

• Eyelid lag or retraction 1
• Exophthalmos (bulging eyes) 2
• Stare appearance 2

Dermatologic Signs

• Localized and pretibial myxedema (in Graves' disease) 1

Cardiovascular Manifestations

• Decreased systemic vascular resistance 1
• Increased cardiac output (up to 300% from normal) 1
• Potential pulmonary artery hypertension 1
• Atrial fibrillation (particularly in older patients) 3
• Potential heart failure in severe cases 1

Diagnosis

• Biochemical confirmation with thyroid function tests:

  • Low or undetectable thyroid-stimulating hormone (TSH) 2, 3
  • Elevated free thyroxine (FT4) and/or triiodothyronine (T3) 2, 3

• Determining the cause:

  • TSH-receptor antibody testing for suspected Graves' disease 5
  • Thyroid ultrasonography 5
  • Thyroid scintigraphy (recommended if thyroid nodules are present or etiology is unclear) 2

Treatment Options

Symptomatic Relief

• Beta-blockers (e.g., atenolol or propranolol) to control heart rate and reduce tremors 1
• Hydration and supportive care 1

Definitive Treatment Based on Cause

Antithyroid Medications

• Methimazole is indicated for 6:
  • Graves' disease with hyperthyroidism
  • Toxic multinodular goiter when surgery or radioactive iodine is not appropriate
  • Preparation for thyroidectomy or radioactive iodine therapy
• Propylthiouracil is an alternative, particularly in first trimester of pregnancy 6
• Treatment duration typically 12-18 months, with 50% recurrence rate 5
• Long-term treatment (5-10 years) associated with fewer recurrences (15%) 5

Radioactive Iodine Ablation

• Most widely used treatment in the United States 7
• Particularly effective for toxic nodular goiter 5

Surgical Thyroidectomy

• Option for patients with large goiters, suspected malignancy, or when other treatments are contraindicated 7

Treatment Considerations for Special Populations

• Subclinical hyperthyroidism (low TSH but normal T3/T4):

  • Treatment recommended for patients >65 years with TSH <0.10 mIU/L 3
  • Treatment recommended for symptomatic patients or those with cardiac or osteoporotic risk factors 3

• Pregnancy:

  • Careful monitoring required as hyperthyroidism increases risk of severe preeclampsia, preterm delivery, and heart failure 1
  • Methimazole generally avoided in first trimester due to risk of congenital malformations 6
  • Propylthiouracil preferred in first trimester, may switch to methimazole for second and third trimesters 6

Complications of Untreated Hyperthyroidism

• Increased risk of all-cause mortality 3, 5
• Cardiovascular complications (atrial fibrillation, heart failure) 1, 3
• Osteoporosis and increased fracture risk 2, 3
• Sexual dysfunction 3
• Adverse pregnancy outcomes 1, 2
• Thyroid storm - a rare but life-threatening emergency characterized by severe acute exacerbation of hyperthyroidism symptoms 1, 3

Treatment Monitoring

• Regular monitoring of thyroid function tests to adjust medication dosage 6
• Monitoring for potential side effects of antithyroid medications:
  • Agranulocytosis (rare but serious) 6
  • Vasculitis 6
  • Hepatotoxicity (particularly with propylthiouracil) 6
• Prothrombin time monitoring during therapy, especially before surgical procedures 6