Senator John Fetterman has been rushed to the hospital after he started feeling “lightheaded”, his office said.
A spokesperson for the Democrat, 53, said on Wednesday night: “Towards the end of the Senate Democratic retreat today, Senator John Fetterman began feeling lightheaded.
“He left and called his staff, who picked him up and drove him to The George Washington University Hospital.
“Initial tests did not show evidence of a new stoke, but doctors are running more tests and John is remaining overnight for observation. He is in good spirits and talking with his staff and family.”
The Democrat from Pennsylvania had previously suffered a near-fatal stroke in May but refused to drop out of a tight Senate race in which he ultimately defeated Republican candidate Mehmet Oz.
Mr Fetterman won 51.25 per cent of the vote statewide in November’s general election, beating the Republican backed by former president Donald Trump, who received 46.33 per cent.
The heart surgeon-turned-TV celebrity spent $27m of his own money after moving from New Jersey to contest the race.
During the remaining campaign race, Dr Oz had made an issue over the Democrat’s health and pushed speculation on whether he was fit to serve as he had refused to release his medical records or allow his doctors to answer reporters’ questions.
He experienced auditory processing issues during recovery and required closed captioning during interviews and debates.
The disorder, a stroke’s common aftereffect, can leave a person unable to speak fluidly and quickly process spoken conversations into meaning.
Mr Fetterman said his doctors had told him that he could have a full recovery.
On election night, he told his supporters that his fight was for “anyone that ever got knocked down that got back up”.
Mr Fetterman previously served as Pennsylvania’s lieutenant governor from 2019-23.
He also served as the mayor of Braddock from 2006-19.
He grew up in a reasonably wealthy family in York, Pennsylvania and had moved to Braddock in 2001 .
