Hyperthyroidismi

Hyperthyroidismi, or hyperthyroidism, is a condition characterized by excessive production of thyroid hormones by the thyroid gland, resulting in elevated circulating T3 and T4 and suppressed TSH. It affects metabolism and multiple organ systems. It is more common in women and typically presents in middle age.

Most common causes include Graves' disease (autoimmune with TSH receptor antibodies causing diffuse uptake), toxic multinodular goiter, and toxic adenoma. Other causes include iodine-induced hyperthyroidism, amiodarone-related thyrotoxicosis, and less commonly pituitary or hypothalamic causes.

Clinical features: weight loss with preserved or increased appetite, heat intolerance, sweating, tachycardia, palpitations, tremor, anxiety, insomnia, goiter; in Graves' disease, ophthalmopathy and dermopathy may occur.

Diagnosis: TSH is typically suppressed; free T4 and/or free T3 are elevated. TSH receptor antibodies support Graves'. A radioactive iodine uptake scan helps differentiate causes (diffuse uptake in Graves', focal uptake in toxic nodules, low uptake in thyroiditis). Consider differential diagnoses such as thyroiditis, drug-induced thyrotoxicosis, and pregnancy-related changes.

Treatment: antithyroid drugs (methimazole), PTU in certain cases; beta-blockers for symptom relief. Definitive options include radioactive iodine therapy or thyroidectomy. Choice depends on age, comorbidities, pregnancy, goiter size, and patient preference.

Prognosis and monitoring: most patients respond well to therapy, but relapse is possible, especially in Graves'. Complications include atrial fibrillation, osteoporosis, heart failure in severe cases, and thyroid storm as a medical emergency. Regular follow-up with thyroid function tests guides therapy adjustments and monitoring for adverse effects.