@auntieheid here is another reference that may be helpful to answer your question...

"What is the difference between Hashimoto's disease and hypothyroidism? Hypothyroidism is a problem with your thyroid gland; Hashimoto's is a problem with your immune system. In Hashimoto's– as in all autoimmune diseases– the immune system gets confused and mistakenly attacks a part of your own body, kind of the metabolic equivalent of “friendly fire”."
--- Do You have Hypothyroid or Hashimoto’s?: https://naturemed.org/do-you-have-hypothyroid-or-hashimotos/