Pennsylvania’s junior senator John Fetterman was hospitalized on Wednesday night after feeling lightheaded near the end of a Senate Democratic retreat.

“Towards the end of the Senate Democratic retreat today, Senator John Fetterman began feeling lightheaded,” said spokesperson Joe Calvello in a statement. “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 stroke, 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. We will provide more information when we have it.”

The 53-year-old defeated Republican Mehmet Oz in a hard-fought campaign for the vacated seat of Pat Toomey in November. More than $300 million was spent during the race, making it the most expensive Senate campaign of the cycle.

Fetterman suffered a stroke on May 13 on a campaign trip to Lancaster, Pa. and has been in recovery since. He still struggles with an auditory processing disorder and has received accommodations to assist him with conducting business in the Senate.

The 6-foot-8 former lieutenant governor of Pennsylvania told supporters on Election Night that he ran for “anyone that ever got knocked down that got back up.”