Causes of Hyperthyroidism*
| Autoimmune | Graves' disease‡ Postpartum thyroiditis |
| Infective | Subacute thyroiditis Pyogenic thyroiditis |
| Neoplastic | Solitary adenoma Toxic multinodular goitre Differentiated thyroid carcinoma (rare, mostly follicular) |
| Secondary | TSHoma Thyroid hormone resistance Hyperemesis gravidarum Hydatidiform mole/choriocarcinoma |
| Destructive | Amiodarone-induced thyrotoxicosis type 2 (AIT-2) Irradiation |
Iodine excess (Jod-Basedow phenomenon) | Amiodarone-induced thyrotoxicosis type 1 (AIT-1) Iodine contrast Dietary (moving from iodine deficient to iodine rich area) |
* Thyrotoxicosis is the syndrome resulting from supranormal thyroid hormone activity. It is usually the result of hyperthyroidism, defined as increased thyroid hormone production by the native thyroid gland. Other causes are oversupply of exogenous thyroid hormone in patients taking levothyroxine or other thyroid supplements, and very rarely, ectopic thyroid hormone production by an ovarian teratoma (struma ovarii).
‡ Pathognomonic features of Graves' disease include the presence of thyroid eye disease, pretibial myxoedema, thyroid acropachy, or a bruit over the thyroid gland.