U.S. Attorney General Michael Mukasey told reporters he feels "great" as he left a Washington hospital on his way to the Justice Department this afternoon.
"As you may have heard, I collapsed briefly last night at the conclusion of a speech," Mukasey said in a statement released earlier today. "All tests at the hospital have come back with good results, and I feel fine."
He also thanked his colleagues for their "good wishes" and "good work."
Mukasey, 67, was delivering remarks on the Bush administration's anti-terrorism policies at the Federalist Society's annual meeting when he collapsed at the podium around 10:20 p.m. ET Thursday.
Justice Department spokeswoman Gina Talamona said doctors gave the attorney general a "clean bill of health" Friday.
Earlier Friday, Talamona said test results had been "reassuring," and that doctors found "no indication that he suffered a stroke or any heart-related incident."
She later added that results from various tests, including a CT scan, MRI, stress echo cardiogram and treadmill stress test, had come back normal. "Everything looks great," she said.
Mukasey spent an "uneventful night" at the hospital and was "very alert." The incident "really appears to have been a fainting spell," likely triggered by hot lights and the late-night speech, Talamona said.
"He is ready to sprint to finish the race. He is really ready to get back to the office," she said, adding that the deputy attorney general, Mark Filip, planned to brief him at the hospital.
Talamona, who said the attorney general "gets up early every morning and works out on the elliptical [machine]," said doctors characterized Mukasey as "very fit."
President Bush spoke to the attorney general this morning before departing for the APEC summit in Peru. "The AG sounded well and is getting excellent care," according to a White House statement.
Former New York City Mayor Rudy Giuliani also spoke to Mukasey this morning. "They had a good conversation and he sounded good," a Giuliani spokeswoman said.
The two men worked together in New York when Giuliani was an assistant U.S. attorney and Mukasey was a federal judge. Mukasey administered Giuliani's oaths of office in 1994 and 1998.
Thursday night's audience members described an impassioned attorney general who was ardently defending the Bush administration's anti-terror policies before he began slurring his words.
Cleveland State University law professor David Forte called it an "extraordinary speech" but said that near the end Mukasey "began to weaken and it was as if he was coming to a conclusion, and then it just faded away."
Robert George, a Princeton University professor who was in attendance, said, "Attorney General Mukasey was well into a speech. He was delivering it articulately, he seemed to be strong and forceful, it was a speech about the efforts of the administration in the war on terror. He gave an account of the administration's policies, defense of the administration's policies, and then perhaps a half-hour into the speech, he very suddenly began to lose balance, and his speech began to slur."
George said he was at a table near the front of the Marriott Wardman Park Hotel's ballroom, and that he and others rushed to the stage after they witnessed the attorney general's fall. Security personnel had already begun to assist him, George said.
After he received emergency first aid from his security detail and a physician attending the event, paramedics transported the attorney general to George Washington University Medical Center, where doctors kept him overnight.
Justice Department spokesman Peter Carr said Thursday evening that Mukasey was "conscious, conversant and alert" at the hospital, and that his vital statistics were "strong" and that he was "in good spirits" and appreciative of the well wishes and prayers he had received.
Bush nominated Mukasey to his post in September 2007. He took the helm at the Justice Department last November after his U.S. Senate confirmation.
Mukasey has been credited with bringing a steady hand to a department racked by scandal. His predecessor, Alberto Gonzales, resigned after a months-long political firestorm over the firings of at least nine U.S. attorneys in 2006 and allegations by Democrats that he misled lawmakers during congressional hearings.
ABC News' John Parkinson and Mark Crudele contributed to this report.