endogenous or exogenous source of TSH.

• Grave's disease
• Toxic multinodular goiter
• Toxic adenoma
• TSH-producing adenoma or pituitary adenoma
• HCG-mediated (gestational) hyperthyroidism
• Thyroiditis
• Drug-induced eg. Amiodarone, iodine contrast

• Factitious hyperthyroidism
• Excessive replacement therapy with levothyroxine

https://www.ncbi.nlm.nih.gov/books/NBK482216/Thyrotoxicosis review 2022