Boxing champ Mike Tyson is “doing great” after suffering a health scare onboard a flight.

The former heavyweight champion became “nauseous and dizzy due to an ulcer flare-up” during an American Airlines flight from Miami to Los Angeles on Sunday (local time).

“He is appreciative to the medical staff that were there to help him,” Tyson’s rep said in a statement to People magazine.

The ulcer flare-up occurred half an hour before the plane landed.

“Mike had some kind of medical emergency on the plane and paramedics boarded,” an eyewitness told In Touch Weekly.

“Before the paramedics arrived, the flight issued an announcement asking for a doctor — the message even came on everyone’s screens.“

Paramedics ultimately boarded the plane to assist the 57-year-old sports star.

“He was in first class, but we were an exit row,” the eyewitness said.

“They asked us to stay on the plane and landed so paramedics could enter. [The stewardess] said something like, ‘He’s a really important passenger so we wanna make sure he’s OK’. I knew it was him, but I just mouthed the words ‘Mike Tyson’ and she nodded her head yes.”

Tyson’s flight had already been delayed for two hours because of an “air-conditioning issue on the aircraft”. A rep insisted that his health scare was not a factor in the delay.

The former heavyweight champion is preparing to face YouTuber and boxer Jake Paul in a match. The much-anticipated event will be held in Arlington, Texas, on July 20.

“I’m very much looking forward to stepping into the ring with Jake Paul at the AT&T Stadium in Arlington, Texas,” Tyson has said previously.

“He’s grown significantly as a boxer over the years, so it will be a lot of fun to see what the will and ambition of a ‘kid’ can do with the experience and aptitude of a GOAT.

“It’s a full-circle moment that will be beyond thrilling to watch; as I started him on his boxing journey on the undercard of my fight with Roy Jones – and now I plan to finish him.”

Paul recently described facing Tyson as the “ultimate test of warfare”.

“I’m going to have to manage the nerves and excitement,” the 27-year-old star – who has turned his focus to boxing in recent years – told TMZ Sports.

“This is my ultimate test of warfare and that excites me.”

-with AAP