Gov. Chris Christie, R-N.J., was hospitalized on Thursday for tests after he had difficulty breathing, the Newark Star-Ledger reported.
The governor was taken to the hospital "out of an abundance of caution," spokesman Michael Drewniak told the paper.
Drewniak added that Christie, 48, has asthma and is "doing fine."
Later Thursday, the Associated Press, citing Christie's deputy chief of staff, reported that an EKG, blood work, and a chest X-ray were "normal." He is expected to be released later tonight.
The first-term governor has consistently ruled out running for president in 2012.