Hyperthyroidism

Causes and Risk Factors

Hyperthyroidism can develop for various reasons:

• Graves’ disease: An autoimmune disorder and the most common cause.
• Toxic nodular goiter: Presence of hormone-producing nodules in the thyroid gland.
• Thyroiditis: Inflammation of the thyroid gland leading to temporary hormone release.
• Excess iodine intake: Through medications or dietary supplements.
• Excess thyroid hormone use: Especially due to overdose during hypothyroidism treatment.

Risk factors include female sex, history of autoimmune disease, smoking, and family history of thyroid disorders.

Clinical Manifestations

Symptoms of hyperthyroidism usually appear rapidly and are related to an increased metabolic rate:

• Rapid heartbeat (tachycardia)
• Weight loss (despite normal or increased appetite)
• Excessive sweating and heat intolerance
• Nervousness, anxiety
• Tremors in the hands
• Diarrhea or frequent bowel movements
• Muscle weakness
• Sleep disturbances
• Menstrual irregularities in women
• Proptosis (eye bulging, seen in Graves’ disease)

In surgical patients, hyperthyroidism can increase the risk of cardiovascular complications and cause heightened sensitivity to anesthesia.

Diagnosis

The diagnosis is made through clinical evaluation and laboratory testing:

• TSH: Usually suppressed (very low).
• Free T4 and T3: Elevated.
• Anti-TSH receptor antibodies: May be positive in Graves’ disease.
• Thyroid scintigraphy: Used for evaluation of nodular structures.

Treatment and Management

Treatment of hyperthyroidism depends on the patient’s condition:

1. Antithyroid Medications

• Methimazole or propylthiouracil are used to suppress hormone production.
• Requires regular monitoring for side effects.

2. Radioactive Iodine Therapy

• Destroys thyroid tissue selectively.
• Often leads to permanent hypothyroidism, requiring levothyroxine replacement therapy.

3. Surgery (Total or Subtotal Thyroidectomy)

• Preferred in cases with large goiter, nodular structure, or resistance to medication.
• Patient must be rendered euthyroid before surgery.

4. Supportive Therapy

• Beta-blockers (e.g., propranolol) are used to alleviate symptoms such as palpitations.

Surgical Considerations

The following points should be noted in patients with hyperthyroidism:

• Preoperative preparation: Surgery should not be performed until thyroid hormone levels are normalized.
• Anesthetic risk: Increased risk of tachycardia, hypertension, and arrhythmia.
• Postoperative monitoring: Patients should be followed for the development of hypothyroidism.

Conclusion

Hyperthyroidism is a treatable condition when diagnosed early and managed appropriately. In surgical planning, assessment of thyroid function is essential to prevent complications and ensure patient safety. Patient education, regular follow-up, and a multidisciplinary approach are the cornerstones of a successful treatment process.