Doctors treating Mayor Thomas Menino said that the 69-year-old leader of Boston has suffered a setback during his hospitalization and that there is no time frame for when he would be released.

Wednesday will be Menino’s 19th day at Brigham and Women’s Hospital. He initially went to see doctors on Oct. 26 when he cut his vacation in Italy short after becoming ill with a virus and blood clot in his leg.

Those issues have been treated, his doctors told reporters during a news conference Tuesday, but Menino also suffered a compression fracture in his vertebrae while hospitalized. He started to recover from that, but in recent days it has become worse, doctors said.

“Our focus is on why his back is hurting more,” said Dr. Dale Adler, who added that doctors are investigating what is causing the increased back pain.

Menino is having therapy twice daily and was in a back brace to help treat the fracture. He is also up and walking around.

Dot Joyce, Menino’s spokeswoman, said the mayor has been in contact daily with his staff and is being briefed.

“Obviously he’s frustrated,” she said. “He’s a guy that likes to be out on the street seeing people.”

Doctors said Menino is on various medications to help with pain, but that he is alert and engaged.

“We have no reason at all to be concerned that the kinds of medications he’s taking have any impact on his ability to be engaged and present,” said Dr. Charles Morris.

Political decisions

Menino has served as the city’s mayor for nearly 20 years, having been elected five times and is the longest-serving mayor in Boston’s history.

Menino would be up for re-election next year, but it is unclear if he plans to run.

When asked yesterday if he made a decision because of his health issues, his spokeswoman said she wouldn’t answer political questions.

“He’s a tough cookie,” said Dot Joyce, the spokeswoman. “No one should under estimate him.”

For now, while he’s in the hospital for the foreseeable future, there are no plans to have the City Council president step in, Menino’s spokeswoman said.