Rep. Bernie Sanders, I-Vt., has left a hospital after he collapsed today while attending the funeral for a Vermont National Guardsman.

Sanders collapsed Sunday at the funeral of Sgt. Joshua Johnson, who was killed last month in Iraq.

Sanders left during the funeral in the Richford High School gymnasium, then fell to the floor in the lobby. He lay on the floor for a few minutes before being helped into a restroom.

Medical crews attended to him for more than a half hour before he walked to an ambulance.

"I feel all right," Sanders, 64, said as he left the building. "My wife had a flu. I'm fine."

His chief of staff, Jeff Weaver, said later that Sanders was taken to the hospital in St. Albans where the diagnosis was a combination of flu and dehydration.

An independent elected to the U.S. House in 1990, Sanders is running now for the U.S. Senate seat held by Jim Jeffords, who is retiring.

Sanders is considered the front-runner for the seat and has the Democratic Party's backing. Among those who have contributed to his Senate bid are Democrats Barbara Boxer of California and Barack Obama of Illinois and Tom Daschle, the former Democratic leader of the Senate.

Sanders, a self-described socialist, started his career as a candidate of the leftist Liberty Union Party, making runs in the 1970s for the Senate and governor and never getting more than 6 percent of the vote.

In the 1980s, he ran for governor and the U.S. House as an independent, finishing second — ahead of the Democratic candidate — in a race for the U.S. House. In 1990 he ousted the Republican and won the state's lone House seat.