Daley is now at Shirley Ryan AbilityLab for a "short stay" as he recovers, according to his physician Dr. Eric Terman.
"Daley and his family deeply appreciate the outpouring of concern and prayers and again want to thank members of the Chicago Fire Department as well as Northwestern doctors, nurses and other staff," his former mayoral press secretary, Jacquelyn Heard said in a statement.
Daley was in his downtown home Wednesday with his eldest daughter, Nora Daley Conroy, when he had what his family called a "health scare."
He was transported from his home to Northwestern Hospital in serious condition and remained there overnight to undergo a battery of tests.
Terman said Daley is expected to make a full recovery.
Former Chicago Mayor Richard M. Daley on April 22, 2013, in Chicago. (Chris Walker/Chicago Tribune/Tribune News Service via Getty Images)
Daley had celebrated his 80th birthday on April 24 of this year. He is the city's longest-serving mayor, leading the city from 1989 to 2011.
He has continued to be active and do workouts, although not at the same level of his physical routine before he suffered stroke-like symptoms impacting his speech in 2014.
Daley has generally kept a low profile, attending social events, including dinners at Gibson’s, but skipping political events. He has refused interview requests from reporters looking to get his take on the increase in crime during the pandemic, particularly in his downtown neighborhood.
In 1976, his father, former Mayor Richard J. Daley, suffered a heart attack and was taken by ambulance to Northwestern, where he died at age 74.
The Sun-Times Media Wire contributed to this report.