One of the doctors treating U.S. rocker and reality TV personality Bret Michaels at an Arizona hospital says he has an "unbelievable fight" in him.

Michaels, 47, is best known as the front man for the band Poison. He is also a contestant on the current season of TV's "The Celebrity Apprentice." He was hospitalized April 22 after complaining of a tremendous headache, which turned out to be a brain hemorrhage.

He is being treated at Barrow Neurological Institute at St. Joseph's Hospital and Medical Center in Phoenix.

"There is no doubt that Mr. Michaels' condition is serious. We are treating the subarachnoid hemorrhage, which caused his severe cranial pain," Dr. Joseph Zabramski said in a statement posted on Michaels' Facebook page Friday.

"Mr. Michaels will continue to undergo testing considering we have hit a few roadblocks including hyponatremia, severe cranial and back pain suffered from blood drainage, an emergency appendectomy performed a week earlier and a lifelong history of Type 1 Diabetes," the doctor added.

"However, Bret's sheer will to live and fully recover is undeniable. He has an unbelievable fight in him and told me what kept him alive at the moment of the hemorrhage was that he 'did not want his family to wake up and see him lying unconscious in the middle of the floor.' It was a combination of Bret's fight to stay conscious during the hemorrhage and get to the emergency room, and the immediate medical attention provided by our staff at Barrow that enabled us to stabilize his condition."