Thyrotoxicosis
Thyrotoxicosis is a clinical syndrome resulting from excess thyroid hormone exposure to tissues, regardless of the source of that hormone. It is distinct from — though frequently used interchangeably with — hyperthyroidism.
Distinction from Hyperthyroidism
| Term | Definition |
|---|---|
| hyperthyroidism | Excess thyroid hormone production by the thyroid gland |
| Thyrotoxicosis | Excess thyroid hormone exposure to tissues (broader) |
Hyperthyroidism causes thyrotoxicosis, but thyrotoxicosis can also result from:
- Ingestion of exogenous thyroid hormone (factitious thyrotoxicosis)
- Release of pre-formed hormone from an inflamed or damaged thyroid (thyroiditis)
- Metastatic thyroid cancer producing hormone
Clinical Presentation
The symptoms of thyrotoxicosis are the same as hyperthyroidism: weight loss, palpitations, heat intolerance, tremor, anxiety, diarrhoea, and muscle weakness.