"In spite of these successes, mass iodine supplementation programs met with much resistance, especially as side effects emerged. While the programs almost completely eliminated goiter, the prevalence of autoimmune thyroiditis increased in areas with iodated water or in those using iodized salt. For example, a threefold increase in autoimmune thyroiditis was noted once iodine deficiency was eliminated in an area of endemic goiter in northwestern Greece, an association confirmed in clinical settings. In one study, dietary restriction of iodine reversed hypothyroidism in twelve of twenty-two patients; seven of the patients with reversed hypothyroidism were re-fed iodine and became hypothyroid again (Anthony P Weetman, Autoimmune Diseases in Endocrinology, pp 50-51)."
Dr Hal Huggins says that autoimmune thyroiditis is due to the high copper-mercury amalgam fillings which started in use in 1976. These fillings are 50 times more toxic than the prior amalgams.
Also, the increase in the vaccine schedules could have caused it as well, especially with their stealth bioweaponized pathogens further killing our immune systems.