From the Guidelines
The most common causes of hyperthyroidism include Graves disease, Hashimoto thyroiditis, and functional thyroid nodules. These conditions are identified as the primary causes of hyperthyroidism in the provided evidence 1.
Causes of Hyperthyroidism
- Graves disease: an autoimmune disorder where antibodies stimulate the thyroid to produce excess hormones
- Hashimoto thyroiditis: an autoimmune condition that can lead to hyperthyroidism
- Functional thyroid nodules: nodules that produce excess thyroid hormone independently of normal regulatory mechanisms Other less common causes include thyroiditis (inflammation of the thyroid), excessive iodine intake, excessive thyroid hormone medication, and rarely, TSH-secreting pituitary tumors.
Risk Factors
Risk factors for a low TSH level, indicative of hyperthyroidism, include female sex, advancing age, black race, low iodine intake, personal or family history of thyroid disease, and ingestion of iodine-containing drugs, such as amiodarone 1.
Diagnosis and Treatment
Diagnosis usually involves blood tests measuring thyroid hormone levels (T3, T4) and thyroid-stimulating hormone (TSH), which is typically suppressed in hyperthyroidism. Treatment options depend on the specific cause but may include anti-thyroid medications (such as methimazole) or nonreversible thyroid ablation therapy (for example, radioactive iodine or surgery) 1.
From the Research
Causes of Hyperthyroidism
The most common causes of hyperthyroidism include:
- Graves' disease 2, 3, 4, 5, 6
- Toxic multinodular goiter 2, 3, 4, 5, 6
- Toxic adenoma 2, 3, 4, 5, 6
- Thyroiditis 2, 4, 5, 6
- Side effects of certain medications 2
- Excess exogenous thyroxine intake 5
- Amiodarone-induced thyrotoxicosis 4, 5
- Choriocarcinoma 4, 5
- Thyrotropin-secreting tumours 4
- Struma ovarii 4
Diagnosis and Treatment
The diagnosis of hyperthyroidism is generally straightforward, with raised serum thyroid hormones and suppressed serum thyrotropin in almost all cases 4. Treatment options include: