The 61-year-old, who is currently awaiting the results of an MRI scan, said he had a dislocated pelvis which is causing him increasing pain.
He told the Irish Independent that the injury happened "mysteriously", and his back is now "out of alignment" because of it.
"I mysteriously dislocated my pelvis and I don’t know how - it’s not as erotic as it sounds," he said.
"My back is now out of alignment as a result.
"Nobody knows what it’s like unless they live with someone who has it. I’m in huge pain and nobody knows how to stop it.”
He added that the pain "hurts like hell” and that he needs to find a way to overcome it.
“It has lasted a month and it feels like I can’t remember what life was like without it,” he said.
Mr Holmes said he has been alleviating his pain as best he can with physiotherapy and "invigorating" ice-cold showers.
Mr Holmes returned to host This Morning this week discussed his health issues.
“I’ve had this a month, I hope I won’t have this much longer, but there are people who have lived with chronic pain their whole lives," he told viewers.
He added that the pain was "too difficult to explain" after Ruth updated viewers on her husband’s condition.
Mr Holmes worried fans after posting a selfie of himself in hospital explaining he was there to find out what was causing “pain like I’ve never experienced in my life”.
The following day, the television personality explained he had suffered “variations” of chronic pain “for years”.
“I’ve lived with variations of chronic pain for years. Don’t allow it to stop me working,” he told followers.