Re: Causes of nodules
Got this from another site. It does not say much. It sounds like you get them or you don't.
Radiation therapy is the only known cause of noncancerous and cancerous thyroid nodules. It was commonly used in the mid-1950s and 1960s to treat enlarged tonsils, adenoids, and thymus glands, and to treat acne. Currently, radiation therapy is not used for these conditions.
Thyroid nodules often develop in people who have never had radiation therapy. Although experts have not established what causes nodules in these cases, certain thyroid conditions (such as goiter) may be associated with their development.
The tendency to develop thyroid nodules may be genetic. Although the gene responsible for thyroid nodules is not known, thyroid nodules run in families.