UFC bantamweight champion Amanda Nunes was forced out of her UFC 213 title showdown against Valentina Shevchenko at the 11th hour when she was taken to hospital after falling ill on Saturday morning.

Through her Instagram account, Nunes revealed that she had to pullout of the contest due to a re-occurring issue with sinusitis, caused by an inflammation or swelling of the tissue lining the sinuses.

“I have chronic sinusitis,” posted Nunes.

“I have fought with it before but this time It didn’t work out, during the weight cut I was unable to breath [sic] and 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.”

Following her withdrawal, Dana White claimed that doctors had cleared the champion to compete. Following the event, the UFC president stated that Nunes’s reasons for pulling out of the fight were “90 percent mental”.

According to Nunes, doctors did clear her for the fight, but only because her blood and dehydration levels were all that were checked. Since then, Nunes claims she has been referred to specialist and prescribed antibiotics.

“I was taken to the hospital after the weigh ins and they only checked my blood and dehydration so cleared me based on that. The next day I went back and they did a CT scan and found a build up and I was prescribed antibiotics and referred to a specialist.”

Nunes also claimed that her rematch with Shevchenko would be rescheduled for a later date.

“I have never pulled out of a fight before. 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. The fight is being rescheduled.