Sharp-eyed fans commented that Richards' neck looked swollen, with many suggesting she had an enlarged thyroid, according to "The Today Show."
Richards, 48, responded on social media Sunday. She said she knew something was wrong, but credits fans for prompting her to make a change.
"A few of you pointed out after 'The Real Housewives of Beverly Hills' reunion that my thyroid was enlarged. You were right, it was something I ignored until pointed out," she said in a post on Instagram.
Richards, a mother of three, said she took action and started a gluten-free diet.
In a recent interview on the Daddy Issues podcast, Richards said she had noticed her swollen neck, but had ignored it, People magazine reported.
“I was like, ‘Why does my neck look bigger?’ I had other symptoms, but I just kept ignoring it and finally when a couple people pointed it out I was like, I have to look into it,” she said.
“It’s amazing to me in a short time eliminating gluten from my diet how much my thyroid has changed,” she wrote on Instagram.
“I had no idea how much our diet really can affect our body and for me how toxic gluten really is ... I thank all of you who sent me messages.”