(CNN) -- Ed Koch, the former mayor who led New York back from the brink of bankruptcy, has been hospitalized for treatment of anemia, his spokesman said Tuesday.
Koch, 87, underwent a blood transfusion at New York Presbyterian Hospital and doctors are observing how he responds, George Arzt said.
Koch was credited with helping rescue the nation's most populous city from bankruptcy and lifting the spirits of its millions of residents in the early 1980s. The Democrat was a three-term mayor from January 1978 to December 1989.
While in office, the ebullient Koch often greeted his constituents with a "How'm I doing?"
After he left office, the popular Koch practiced law, eventually hosted a radio show, was a newspaper columnist and parlayed his nationwide fame into countless appearances on TV series as himself. He even hosted "The People's Court" as the judge for two years.
Recently Koch also re-thrust himself into the political spotlight. In 2011, he supported a Republican candidate for Congress in a very Democratic district after President Obama called for Israel to return to its pre-1967 borders. But after Obama expressed support for Israel at the United Nations during a Palestinian bid for statehood, Koch said he was back in the president's camp.
CNN's Chris Boyette contributed to this story.