UFC bantamweight champion Amanda Nunes blamed chronic sinusitis for her decision to drop out of her title defense at UFC 213 with just a few hours’ notice.

Nunes revealed her condition in postings Sunday on Twitter and Instagram. Nunes made a trip to the hospital on Saturday and decided not to fight later that night, infuriating the UFC and opponent Valentina Shevchenko.

Nunes, who beat Ronda Rousey in her last bout, said she felt out of breath during her weight cut. She also “felt off balance from the pressure in my sinuses. I was not feeling well enough to risk getting punched in the head with such pressure.”

“I have never pulled out of a fight before,” Nunes wrote. “I am sorry to all my fans that came out to see me. I’ll make it up to you the next time I step in the cage.”

UFC President Dana White and Shevchenko sharply criticized Nunes for her decision, which forced the promotion to scrap the main event of its pay-per-view show. Shevchenko ripped Nunes for attempting a drastic weight cut, making her more susceptible to illness and many other health problems.

“You can’t just say, ‘I don’t want to fight,”’ Shevchenko said.

White was frustrated by Nunes’ unwillingness to fight despite having no major injury and being medically cleared to compete.

“You can’t make anybody fight,” White said Saturday night. “(Nunes) just said, `I don’t feel right.’”