Suni Lee -- the Olympics star who won gold in Tokyo in 2020 -- just revealed her kidney issues this year caused her to gain 45 pounds.
The 5-foot gymnast made the revelation in an interview with USA Today this week ... just a few months after she left Auburn to get a handle on the ailment.
"I couldn't fit into any of my clothes," Lee told the outlet. "My eyes were swollen shut. It was just so scary.