Toxic multinodular goitre (Plummer's disease) - nodules develop on the thyroid gland that act independently of the normal feedback system and continuously produce excessive thyroid hormone.

Most patients are aged over 50

Second most common cause of thyrotoxicosis (after Grave’s)

Goitre with firm nodules

Nuclear scintigraphy reveals patchy uptake.

The treatment of choice is radioiodine therapy.