Ronda Rousey says concussions led to UFC/WWE retirement

March 21 (UPI) -- Combat sports legend Ronda Rousey says concussions led to her retirement from mixed martial arts and professional wrestling.

Rousey made the comments Wednesday on her Instagram. The 37-year-old went 12-2 in UFC. She lost her final two fights, via knockouts, to Holly Holm in 2015 and Amanda Nunes in 2016.

"My concussion history, I had to keep [it] secret for years, so I would be able to continue to compete and perform," Rousey said in her Instagram video, while promoting her new book, Our Fight. "That's basically why I had to retire."

In 2012, Rousey became the first woman signed to UFC. Her first 12 winning fight launched her into superstardom.

Rousey, who went on to compete in WWE and other wrestling events, was inducted into the UFC Hall of Fame in 2018.

"I think that there was just so much to [the Holm loss], that I couldn't talk about it in the form of like an interview or an article or anything like that, or there would be several filters between my words and people reading it," Rousey said.

"So much had to do with having so many concussions when I was in judo before I even got into MMA. I couldn't talk about it at all when I was doing MMA because it would literally put a target on my head, and I might not have been allowed to compete any further. The same thing with WWE."