A spokesman for Commerce Secretary John Bryson said the cabinet member suffered a seizure before being involved in two traffic accidents over the weekend in Los Angeles.
The accidents are under investigation by law enforcement officials.
Jennifer Friedman, a Commerce spokesperson, said Bryson was taken to the hospital for examination and remained overnight for observations. She said the secretary had returned to Washington after being discharged.
"The investigation is ongoing," she added.
A senior official said Bryson was not on department business or in a government vehicle when the accident occurred and was not traveling with a security detail.
A spokesman from the San Gabriel Police Department said Bryson was cited for a felony hit-and-run after the incident, CNN first reported.
A police report cited by CNN said Bryson had been driving a Lexus and rear-ended another vehicle which was stopped at a railroad crossing.
The Obama Commerce secretary allegedly spoke to the occupants in the other vehicle, before leaving the scene, in the process striking the other car again.
He then allegedly struck a second vehicle driven by a couple in the neighboring city of Rosemead, the police statement said.
Officers arriving on the scene found him unconscious in his car and he was taken to a local hospital for treatment.
A police statement said the investigation was still in its “preliminary stages.”
“At this point in time, there is no indication that alcohol or drugs played a role in the collisions,” said the police report.
White House press secretary Jay Carney on Monday said President Obama was "concerned" about the incident and about Bryson's health.
Carney said Obama had not yet spoken to Bryson, though his chief of staff, Jack LewJacob (Jack) Joseph LewThe Hill's Morning Report - Biden argues for legislative patience, urgent action amid crisis On The Money: Senate confirms Yellen as first female Treasury secretary | Biden says he's open to tighter income limits for stimulus checks | Administration will look to expedite getting Tubman on bill Sorry Mr. Jackson, Tubman on the is real MORE, spoke to him Monday morning. The White House was first notified of the accidents Sunday evening.
"[We're] still in the process of gathering information," Carney said, adding there’s "still more that needs to be learned."
On Monday morning, American Crossroads, the group backed by Karl Rove, appeared to get ahead of themselves on Twitter when they suggested that Bryson's accident occurred because he was under the influence of alcohol.
But the group quickly deleted the Tweet and sent out an apology on Twitter. "Earlier Bryson tweet with hashtag #skills attempted levity (before facts known) and failed miserably. We took it down and regret the tweet," the GOP group said.
A short time earlier, the group had written: "How does @CommerceSec have 3 car crashes in 5 minutes and alcohol not be involved. #skills."
Bryson, who is 68, was sworn in as Commerce Secretary in October 2011. He previously worked as Chairman and CEO of Edison International, a public utility company based in Southern California.
This story was updated at 11:05 a.m. and 2:00 p.m.
— Alicia Cohn and Amie Parnes contributed