Kayla Harrison says she was “peeing blood” in the week before her win over Ketlen Vieira at UFC 307 last Saturday.

The two-time Olympic judo champion’s victory lifted her into the number one contender spot for Julianna Pena’s bantamweight title.

Harrison has fought most of her MMA career at lightweight (155lb) but competes at 135lbs in the UFC.

The 34-year-old secured a points win, but thought her performance was affected by her health issues going into the contest.

“I need to take a little bit of time off just because of the weight cut and the process that it is for my body,” Harrison told TMZ.

“I’m just not built to weigh 135lb. Anytime I get under the 150s, it’s not pleasant.

“The first time [I fought in the UFC] was [the] fear of, like, ‘Can I do it?’

“This time it was fear of, like, ‘Oh God, I have to do it’. The anticipation. But I’m blessed. I have such a good team.”

The UFC was aware Harrison attended the hospital the week before her bout, but the fighter did not elaborate on what caused the problems.

Harrison is a two-time lightweight champion in the PFL, but left the organisation to join the UFC earlier this year.

The Ohio fighter submitted former champion Holly Holm in her debut before beating Vieira.

Pena dethroned Raquel Pennington in a controversial split decision points win at UFC 307, but opted to call out retired champion Amanda Nunes rather than Harrison after her victory.