If the thyroid gland is growing rapidly or one or more of nodules raises concern following investigation, then surgery may also be recommended. Diffuse goitre This is often caused by autoimmune thyroid conditions such as Hashimoto’s thyroiditis and Graves’ disease and can be associated with an over- or an under-active thyroid.
https://www.btf-thyroid.org/thyroid-nodules-and-swellingsleaflet